Check Engine Light After Emissions Test

Check Engine Light After Emissions TestI really didn’t care until now I’m close to my emissions test deadline. If the vehicle fails the second test, a waiver may be issued. Hopefully, this will get rid of the check engine light once and for all. If this doesn’t work, it’s not necessarily proof that there’s a deeper problem at play. Free Check Engine Light Diagnostic Testing. The test takes a few minutes to complete. If you perform a procedure to pass an emission test when your check engine light is on, you can turn off your check engine light by using a scan tool, or you can do it by disconnecting your vehicle's battery. Proceed to start the engine and let the code reader display the check engine light codes. Avoid Emissions Testing engine light will be a serious concern that could cause you to fail your test. If you currently have a check engine light, it means you have a code for a problem that affects emissions. Passing An Emissions Test With A Check Engine Light On. If you aren't getting the right air/fuel mixture, your engine might stall or refuse to start. nashvilleyall19 said: I recently had my 2015 Chevrolet Cruze checked for what smelled like my engine burning. When the light comes on, one or more diagnostic trouble codes are stored in the car's computer. Loose fuel cap. Emissions Tests and Check Engine Light. This particular sensor measures and . 5 common reasons for the check engine light to come on are: Gas Cap; If you jumped back in the car too quickly after pumping gas, it's possible your gas cap didn't close properly. Step 1: Clear the Check Engine Light if it is on. The Check Engine light may come on some time after filling up if your gas cap is not closed properly. The check engine light technology is tailored towards emission control and when that of your car turns on, it indicates that the internal health of the engine is threatened. The door is usually locked, you’ll find a push button to unlock it. What can YA101 OBD2 Scanner do ? 1. The busiest times for vehicles testing is towards the end of the month and on Saturdays. If the PCM continues to command the check engine light to remain illuminated, an emissions related problem is indicated. When the ECU senses something wrong, it indicates the problem through the check engine light. If this particular warning light is on you will need to. The oxygen sensor, or O2 sensor, is a device that measures the oxygen levels in your car’s exhaust system. Other common reasons for a Check Engine Light are dirty mass airflow sensor, faulty emissions control part, a malfunction with the fuel injection system, . Loose Gas Cap: Your gas cap is loose, broken, or simply missing. Quite simply, the check engine light is a signal from the car’s engine computer that something is wrong. The computer must be driven for at least 100 miles after it has been reset to pass an emissions test in order to re-learn your habits. If your Check Engine light comes on and stays on, your car is telling you that your emissions controls aren't working properly. In this video, I explain how to clear a check engine light and pass an emissions test. Here are some tips to keep in mind to ensure passing a Nevada vehicle emissions test: Make sure the vehicle does not have its “Check Engine” light on; If it does, it will not pass the test. Discussion Starter · #1 · Jul 29, 2005 Can an emission inspection cause the "Check Engine" condition or is it just a coincidence? Several days ago an annual inspection was done on my '98 ML320, which it did pass, but in a about an hour the "Check Engine" light came on. I took my car back to the same mechanic a week later and said it still smelled like something under. Once all of these things have been taken care of, how long does it. Can an emission inspection cause the "Check Engine" condition or is it just a coincidence? Several days ago an annual inspection was done. How To Fix Check Engine Light Gas Cap. There are dozens of trouble codes that will cause the . The first time I was cruising to work, taking it easy and going around 60 on the highway. The check engine system checks hundreds of different parts of your car every second. Press and hold the horn for 30 seconds or try to switch on the vehicle's lights. If repairs end up being costly, a failing test is the first step in the waiver process. To fix, check to make the gas cap is on tight. First, check the gas cap to make sure it wasn't left loose after refuelling. Driving your car will help it pass the emissions test. If the light remains on after a day, contact us at (909) 891-0121. Check engine lights come in orange, yellow or amber, depending on the manufacturer. These codes will stay there even if the light goes out. Can i pass emissions with check engine light on? If you have a “Check Engine” light on, your car will not pass an emissions test. when a vehicle has an emissions system problem, it almost always triggers a check engine or service engine soon light. Immediately after, emissions test my check engine light is flashing and engine fan cycles. Using a Trouble Code Scan Tool. This will reset the engine control unit in many car models. In the state of Virginia you will not pass the emissions test with . In this video, I explain how to clear a check engine light and pass an emissions test. If you take your car to a certified repair technician, he should be able to diagnose the reason why your check engine light/MIL is illuminated and give you an estimate to have the problem fixed. Let's say you just fixed your car and need to clear a code, or you des. However, if you have a check engine lighton, you’re going to automatically fail the test. If a mechanic fixes the cause of the check engine warning on your car, they should reset the diagnostic system to clear any codes. Georgia Emissions Testing. Easy Solutions for a Check Engine Light & Passing Your. An “Advisory” will continue to fail vehicles aged 12. The last two times I was parked and the truck was idling. If you're performing this procedure in an effort to pass an emissions test when the check engine light or service engine soon light is on or illuminated, read on and in detail to learn how the. If it is dark, take a flashlight with you. This will test the O2 heater, Passive Air, Purge "No Flow", Misfire and if closed loop is achieved, Fuel Trim. The P0496 is probably related to your trouble starting the car after getting gas. com, “the engine and the emission control system are so interlinked that . After a few minutes, turn the ignition on again and the light should be off. Mechanic's Assistant: Does the light stay on, or does it blink? Check engine light is blinking. The following vehicles must successfully complete an OBD emissions test:. If the light begins flashing, it indicates a more serious problem such as a misfire that can quickly overheat the catalytic converter. Diesel Emissions Inspection (smoke opacity test). They will tell you if it needs to be turned off. Ironically, they aren't really attached to the engine. Common Causes for BMW Check Engine Light · Loose Gas Cap: Your gas cap is loose, broken, or simply missing. Yep, evap system small leak detected. Your check engine light can lead to many serious issues and having it taken care will help you avoid far more costly issues down the road. In most states, an illuminated "check. Evaporative Emission Control System (EVAP) Self Test. Why Do I Have Codes But No Check Engine Light? There is a possibility that the codes are from a previous problem, which has already been repaired, if the check engine light does not come on. It can be due to a faulty engine sensor or any other damaged part in your engine. But get the test taken, get the failed report and bring it to us. After a few minutes, turn the ignition on again and the light should be off. A service technician will turn off the dashboard “check engine” light after most repairs. No ifs, ands, or buts about it. Fast forward to today I'm driving down the. It wasn't a big deal to me, until I had an emissions test. If the vehicle fails the second test, a waiver may be issued. Alternately, drivers may complete a smog check while out of state if the state they are in conducts emissions testing. Guide to Reset Check Engine Light: With & Without Tools. Your oxygen sensors are another emissions system part that will trigger your Check Engine light. In fact, the check engine light is sure to come on if the Catalytic converter is dying Mass airflow sensor is malfunctioning Oxygen sensor is malfunctioning. These types of trips don't give the computer enough time to properly adjust. If it is not, tighten it and drive around to see if the light goes off. One sensor in particular that can potentially trigger your check engine light is the mass airflow sensor. Arizona Emissions Testing – Everything You Need To Know. Each time it was a P20EE code (pulled with my own scanner). Basically, a check engine light is a device which indicates that the Onboard Diagnostics (OBD) of a car's computer has detected a problem in the car. It doesn't matter if there is no reason behind the check engine warning. Most vehicles have between two and four oxygen sensors, and if any of those are faulty, it . If during the readiness test a component fails the code is set and data is recorded and the check engine light is on. Mechanic's Assistant: Are you fixing your Forester yourself? What have you. A failing or clogged catalytic converter can severely impact . This resets the vehicle’s emission system components to “not ready”. Like/Comment/Subscribe/Share!!!Camera Used (Affiliate):Canon M50: http. Illinois Emissions Testing & Smog Check. Any interruption in the flow of electricity to the spark plugs will stop them from working. It is possible that fuel additive usage and CEL coming on was just a coincidence. #1 - Your Fuel Cap is Loose This is one of the most common, and fortunately, easiest to fix, reasons that your check engine light can come on. When your check engine light is on, connect the scanner to the OBD connector situated under most car models' steering portion. The primary reason OBD II was invented is to reduce smog emissions caused by malfunctions, but it is also valuable as an alert to the driver that something. Once all of these things have been taken care of, how long does it take after resetting check engine light pass an emissions test? It primarily depends on how much carbon has built up due to lack of use over time and how well the system maintained before turning off during storage. Check engine light code P0440 means Evaporative Emission Control System Malfunction. Also, many of these issues may lead to a failed emissions test on the Tennessee side of Memphis. If your check engine light goes on shortly after you've filled up at a gas station, check to make sure the gas cap is on tightly (or that you . There are a number of issues that can make the check engine light come on. Evaporative (evap) emission canister or fuel tank leaks. In January, Illinois initiated a new emissions test for cars from the 1996 model year and. Emissions Alert: Your Check Engine Light. Tucson vehicle owners must get a smog check every two years who own a gasoline vehicle made in the 1996 model year or newer model year weighing less than 8500 lbs. A blinking check engine light means that the onboard diagnostic system detected a problem with the engine. To pass an OBD-II emissions test, a vehicle must: Have a functional 'Check Engine' light and OBD port. The check engine light illuminates for engine problems, including problems with emissions control devices that will cause your car to fail an emissions test. Either way, it's an automatic fail until you repair the problem. Check engine light and failed emissions test. Or the "Check Engine" light illuminated for light duty vehicles of 1996 and newer. Most Common Reasons Your Check Engine Light is On. And of course, make sure that the cooling fans are working correctly. Is your check engine light on? Here are 10 possible reasons why · Oxygen sensor failure · Loose fuel cap · Catalytic converter failure · Spark plug/ . It works for almost all 12V 16PIN OBDII car after 1998 year. Toyota Corolla Check Engine Light in Roswell. Turn off your "Check Engine" light (if needed). start the vehicle and let it idle for two to three minutes in park or neutral. Tighten the top with your wrench, and make sure the cap is back where it should be. Successfully complete the OBD-II system monitors that are built-in to the vehicle. She has 22000ish miles on her and yesterday I went to get her a Pa state inspection and emissions test. You are correct in that it comes on most of the time because something is wonky with the emissions system. Leave it disconnect for 5 minutes. Quick and easy way to past the dreaded emissions test if you have a check engine light. 1996 and newer vehicles CANNOT PASS emissions testing with the “Check Engine” light illuminated. Evaporative (evap) emission system hose leaking. How to Pass an Emissions Test. When is an odb2 scanner, can read/clear codes, live data, freeze frame, smog check, o2 sensor test, on-board monitor test, component test, view VIN to help you reveal why the engine light is on, avoid being fined before the annual car inspection and keep your engine in good condition. The bill directs the air quality control commission to submit to the federal environmental protection agency by May 5, 2021, a. Check your gas cap if the light comes on suddenly. As far as going fast: 1) warmed up motor, transmission is a MUST. The Check Engine Light means there is something wrong with your engine’s electrical system. Why Is Your Check Engine Light On?. A flashing check engine light is usually an indication of a very serious problem, like an engine misfire. After requesting a test extension, the state sends motorists a notice 6 to 8 weeks before the new testing deadline. Below we have highlighted the most common causes of a check engine light. If you have a “Check Engine” light on, your car will not pass an emissions test. Smog Check Stations in Joliet, Illinois. You won’t know this, however, until your vehicle has been smog tested. The only way to know for sure is to have your vehicle inspected by a trained mechanic. The button should be located under the steering column or the floorboard beside the driver's side seat. 1996 and newer vehicles with on-board diagnostic (OBD) equipment will not pass emissions testing if the check engine light is on. 6 is Proof of insurance on the vehicle itself (not just the driver). After downloading the app on your phone, you can scan over 7,000 diagnostic trouble codes, clear your check engine light, and even set up separate accounts for different vehicles. If the light begins flashing, however, it indicates a more serious problem, such as a misfire that can quickly. Turn on the AC on full blast and make sure that the fans are spinning. If it doesn’t, there may be a more critical factor causing this item to turn on. There are thousands of possible codes for a check engine light and we can't cover all of them here. The Engine Control Unit or ECU is the unit that monitors the components of the car to detect any problems. Sometimes, this can trigger the light. While it is quite easy to clear check engine light from illuminating on your dashboard, it can not be an escape route to pass emission tests. However, there are literally 100s of codes that can cause the check engine light to come on. Codes can be intermittent, but once a code is set the data is in the ECM as a pending code. It is a gas at standard temperature and pressure, but compressible to a transportable liquid. Check 1 - Malfunction Indicator Lamp (MIL) or Service Engine Soon Light, Check Engine Light, Check Engine Symbol check This is considered the bulb check portion of the test. This light, often called a “check engine light” in vehicles made before 1996, generally indicates an engine problem that will impact your emissions test. Your next test involves disconnecting the negative battery cable and forcing your electronic systems (and your in-vehicle diagnostics) to perform a hard reset. If your CEL is not related to emissions, have your vehicle taken to a mechanic for further inspection and possible repair or adjustment. However, as with all check engine light diagnostic trouble codes. There are a few things you can do if you don’t. The Complete Guide To The Check Engine Light. If you take your car to a certified repair technician, he should be able to diagnose the reason why your check engine light/MIL is illuminated and give you an estimate to have the problem fixed. Carbon also builds up in the engine's oil. Use a scan tool on your vehicle to help locate the issue and guarantee you will pass your emissions test. On-Board Diagnostic Test. After requesting a test extension, the state sends motorists a notice 6 to 8 weeks before the new testing deadline. You must also turn off the check engine light or the service engine light before the emission test so that you can pass the smog inspection. Sound may be heard coming from underneath the luggage compartment for several minutes. Will My Car Pass Inspection If I Reset The Check Engine Light?. Your car will not pass an emissions test with an illuminated check engine light. Everything You Need to Know About the Check Engine Light. Many Chevrolet dealerships will perform a free diagnostic test to identify the reason your. The check engine light comes on and stays on. A set of errors will display, write down these trouble codes, and keep them safe. Step 1: Clear the Check Engine Light if it is on. Approximately 15 seconds later, one of two things will happen: The MIL will flash for about 10 seconds and then return to being fully illuminated until you turn OFF the ignition or start the engine. This includes everything from how the car fuels . The P0496 is probably related to your trouble starting the car after getting gas. The ‘Check Engine’ warning light is off. The original mechanic replaced the heating hose and said it had cracked. 997 - Check engine light after emissions test - So I had to get my car inspected yesterday Full emissions test on the dyno, etc. A service technician will turn off the dashboard "check engine" light after most repairs. Schedule an Appointment Schedule. A Check Engine Light (CEL) on a car may indicate an emission problem with the vehicle. The problem may be oxygen sensor failure, loose fuel cap, Catalytic converter failure, ignition coil issues, bad spark plug wires, or a mass airflow sensor failure. If the vehicle is operating out of the allowable ranges, the computer turns on the "Check Engine" light on the dashboard. Here’s how: Connect to the OBDLink app. This is another common reason for a check engine light to come on. An excessive gap can also be the culprit for the spark plug's malfunctioning. Avoid these times for a quick test and faster wait times. It’s linked to the car’s emissions system. If your check engine light is on, this is an instant test failure. If your emissions test is coming up soon and your check engine light is on, use TalkLocal for free to find a qualified mechanic to find and fix the problem with your engine immediately! Don’t risk failing the emissions test; fill out a service request on TalkLocal’s website now! This entry was updated on Wednesday, June 17th, 2015 at 3:37 pm. Though you can turn off the check engine light, it won’t help you pass the test. This includes everything from how the car fuels (i. This will allow you to fix any emission issue and assures you that your vehicle is ready for the test. As soon as you turn the ignition switch to the ON position, you will see the MIL (Check Engine Light) symbol come on as part of a normal bulb check. If the check engine light is on constantly during driving with no noticeable driving or performance problems, there is a permanent fault in the emission control system. The status remains “not ready” until the vehicle’s computer has had adequate time to review the repaired component. If you think that your vehicle feels different on the road, especially if the performance has decreased, reduce your speed and avoid transporting heavy goods. Check engine lights come in orange, yellow or amber color depending on the manufacturer. This check is done approximately five hours after the engine is turned off. It's linked to the car's emissions system. Most OBDII-equipped vehicles have a gas cap . Well, the answer is it depends. In fact the computer double and sometimes even triple checks the emissions trouble. For many drivers with older cars, it's a likely reason the Check Engine Light came on. Quick and easy way to past the dreaded emissions test if you have a check engine light. Fuel and air metering systems problems · Ignition system faults · Transmission issues · Bad Spark Plugs · Emissions controls issues · Computer output circuit issues . Discussion Starter · #1 · Jul 29, 2005. However, mundane issues like forgetting to put your gas cap on can also cause the light to come on. But according to Dan Edmunds, director of vehicle testing for Edmunds. During testing, your car’s computer is connected to a computer at the testing center, which “asks” your car’s computer about the status of various emissions tests and readings that your car’s computer performs. Rislone Complete Gasoline Fuel System Treatment (p/n 4700, or 4740 for diesel cars and trucks) – six additives in one bottle. How to Reset a Check Engine Light: 7 Steps (with Pictures). Drive your car as you normally would. The test takes a few minutes to complete. In some states, your vehicle will receive . Check gas cap. Why does my check engine light flash 10 times? It means that one or more of the emissions systems is not ready, also known as the I/M readiness test. The oxygen sensor monitors and measures how much fuel the car burns. A problem with any of these parts can cause the light to come on. If the check engine light does not . Although the exact causes vary depending on the type of vehicle, the most common cause of the check engine light coming on is a faulty oxygen sensor. This system monitors a number of engine and emissions-related components; to ensure that everything is in working order. The check engine system checks hundreds of different parts of your car every second. That said, it is important to note that the OBD-I and OBD-II models . If the check engine light turns on right after a fill-up, make sure that the gas cap isn't loose or improperly sealing. Often, owners will reset this item for inspection. ago Yep, evap system small leak detected. While a check engine. A loose gas cap is a common problem. How to Pass an Emissions Tests. The quicket components that set off the alert are the fuel-air . When these problems happen, the check engine light can turn on. There's a chance that after using a tank or two of new, quality gas in your car, the check engine light will turn back off. Check Engine Light and Emissions Testing. Furthermore, if your check engine light is on, you cannot pass an emissions test. I'm sitting in the dealer's service area right now. After, you will need to drive. Sometimes problems that cause the CEL can be fixed without any need for major repairs or adjustments. converters—all things that would trigger one or more of a modern vehicle's many monitors, illuminating the dreaded check-engine light. You forfeit your inspection fee if the emissions testing center does not offer a free re-test. Hopefully, this will get rid of the check engine light once and for all. The Check Engine Light (MIL). An illuminated “Check Engine” light will start emitting emissions in vehicles aged eight (8) to eleven model years from January 1, 2015. The only problem was that I had to bring it in twice to get it fixed properly, and the scheduling is a. Find out how to fix it in this article! 1. Propane (/ ˈ p r oʊ p eɪ n /) is a three-carbon alkane with the molecular formula C 3 H 8. Turn off the air conditioner and all the other loads and apply half throttle until 88km/hr (55mph) is reached. Make sure the vehicle does not have its “Check Engine” light on; If it does, it will not pass the test. Quite simply, the check engine light is a signal from the car's engine computer that something is wrong. Generally, if the check engine ligh. The “Check Engine” Light May Be Caused By A Defective Sensor · You Might Pass The Test If The Problem Is Fixed · Have Your Vehicle Taken To A . The reason is that the ECU performs several start-up tests during the next few driving cycles. But there is something you can do to pass the retest: Drive your car. The check engine light is linked to your car's computerized systems, which allows it to notify you of minor conditions—such as a loose gas cap or bad spark . Why is My Check Engine Light On?. this signals that an emission system . The gas cap was tight, I checked it first after the CEL came on. Despite the fact that it had been several months since I bought the car, they fixed it for me free of charge. The check engine light, often referred to as the Malfunction Indicator Lamp or MIL, allows the PCM to alert the driver that an emissions related problem has occurred or is currently occurring. If the light is on, you’ll need to get the problem that triggered it fixed prior to testing. If the MIL is illuminated but not blinking, first check to see whether the fuel-filler cap is loose or missing. You are allowed to test your vehicle if the check engine light is on. After a check engine light reset, the system takes . The check engine light is located on the dashboard panel and is colored red or yellow. What Is a Check Engine Light?. ABS: Diagnose the braking systems of most 2006 and newer domestic and Asian vehicles. Sometimes the cap needs to be replaced, but it's not. Determining what has caused the "Check Engine" light. Having a check engine light on will make you fail the emission test. A blinking light, rather than a steady light, often indicates a serious engine misfire. The check engine light is constantly on: Your vehicle's onboard diagnostic system has determined something is wrong and needs to be fixed. Since, it is ‘not allowed’ to have the check engine light on while getting the emission test, then the alternative way is to kill the check engine light or have it reset and afterward go get their test before it goes ahead once more. The status remains "not ready" until the vehicle's computer has had adequate time to review the repaired component. The 'Check Engine' warning light is off. What Factors Are Needed To Pass Emission Tests? The ‘Check Engine’ warning light and OBD port have been functional. Here's how: Connect to the OBDLink app. If your check engine light is on, get your vehicle tested anyway. Having to put your vehicle through another round of. Ignition system faults · Emissions controls issues · Transmission issues · Computer output circuit issues · Loose Gas Cap or Missing Gas Cap · O2 Sensor · Bad Spark . Match sure it is tight, on right, and has no cracks in seal. If a vehicle’s Check Engine Light is on before taking an Arizona vehicle emissions test, the vehicle fails the test until the owner gets the car repaired and the Check Engine Light is no longer on. As mentioned, during the taste, an expert technician connects a device to the car to read the vehicle's onboard computers. [6] 3 Wait 15 minutes and reconnect your battery. If the light is on, you'll need to get the problem that triggered it fixed prior to testing. The check engine light is a pointer that there’s a shortcoming in the emanations framework. We suggest that you unscrew the gas cap and re-tighten until it clicks, then allow the gas cap check engine light up to a day to reset. If it doesn't, there may be a more critical factor causing this item to turn on. If the light is on, you’ll need to get the problem that triggered it fixed prior to testing. Basically, a check engine light is a device which indicates that the Onboard Diagnostics (OBD) of a car’s computer has detected a problem in the car. If you jumped back in the car too quickly after pumping gas, it's possible your gas cap didn't close properly. In 2016, this requirement applies to model year 1982 through 2005 vehicles and so on. Yes, I passed the test, but my concern now is if it was just a fluke or the two . If it has a short, the short must be fixed. It is true that your vehicle's emissions system will trigger a check engine warning if something is wrong, but there are other reasons why . If you're trying to pass a smog test, clearing the check engine light isn't a fix. Illinois-registered drivers with vehicles that require testing, and living in or around Will. The Engine Control Unit or ECU is the unit that monitors the components of the car to detect any problems. Make sure the “Check Engine” light is off. Below is how to pre-test your vehicle first: Make a connection to your OBDLink. Since, it is 'not allowed' to have the check engine light on while getting the emission test, then the alternative way is to kill the check engine light or have it reset and afterward go get their test before it goes ahead once more. It is never a good idea to ignore a check. One key reason the light goes on is due . It works for almost all 12V 16PIN OBDII car after 1998 year. fuel trims) to how efficiently the 3 way catalyst (catalytic converter) is working. The vehicle must fail the carbon monoxide or hydrocarbon levels exceeding the set standards for 1968 - 1995 for light duty vehicles and all heavy-duty vehicles. I hadn't even taken the car out of the dealer's driveway, so they. Gas cap issues can reduce fuel pressure and allow fuel vapors to escape, reducing fuel economy and increasing harmful emissions. The main answer is that after you clear the car’s internal computer, the engine control unit, you will need to continue driving for around 50-100 miles to determine the answer to how long does it take for the check engine light to come back on after reset. A well maintained, properly functioning vehicle uses less fuel and creates less exhaust emissions. How To Turn Off The Check Engine Light? Check Engine Light, Service. It basically means that evap flow is detected when its not supposed to be. When the mass airflow sensor fails, your check . The vehicle's computer is monitoring that pressure at all times when your vehicle is running. This means driving it around for at least 30 minutes to get the engine up to operating temperature. If the light is on, you’ll need to get the problem that. Bad compression: A burnt or bent valve, worn piston rings, or valve timing that is off will cause a misfire as well. Turn off the engine vehicle. Before the test may be passed, there is a fault with the emission system that must be solved. Moreover, with a check engine light turned on, you won't be able to pass the emissions (smog) test and detect new problems in the internal system. No, you cannot pass emissions with the service engine light on. If the mechanic disconnected the light, you will not see it when starting the engine. The catalytic converter is a vital part of the emissions system, removing toxic carbon monoxide. Bring your vehicle to a smog test location that retests for free. 5 is Vehicle registration documents. · Failing Catalytic Converter: Your catalytic . On-Board Diagnostics is a computer-based system built into all 1996 and newer light-duty passenger vehicles to monitor the. Keep the sealing surfaces in the cap clean so it can make a good seal. Easy Solutions for a Check Engine Light & Passing Your Emissions. I had a small problem with the check-engine light coming on in my car. Make sure the "Check Engine" light is off. It wasn't a big deal to me, until I had an emissions test. The vehicle must fail the carbon monoxide or hydrocarbon levels exceeding the set standards for 1968 – 1995 for light duty vehicles and all heavy-duty vehicles. OBD Testability Issues Some vehicle models are known to have issues that interfere with the successful completion of OBD readiness monitors. Modern vehicles have an automotive diagnostic system known as, OBD-II (on-board diagnostics). Below we have highlighted the most common causes of a check engine light. You may need to take it to a professional to see what the true problem is. Let's say you just fixed your car and need to clear a code, or you desperately need to pass the. You will need to use a scanner to find out the root cause of your check engine light and fix the issue before you will be able to pass your emissions test. Loose gas cap: As simple as it may sound, a loose gas gap is a very common cause for a check engine light.