Different states have an emission test with the aim of reducing vehicle emissions as an environmental concern. The reason for the test is to ensure your car is not emitting harmful gases into the atmosphere. The test helps to keep the environment safe and reduce the carbon footprint of your vehicle. Each state has different tests, but will your car pass the check with the engine light on?
No, a car won’t pass an emission test with a check engine light on. If you have disconnected the battery or the trouble codes deleted, you will have to drive the vehicle under varying conditions for around one week before it will pass. Kindly get rid of any tools that monitor your driving habits before a test and replace it afterward. A check engine light is an indicator something somewhere is wrong. That something could affect your smog check results.
How to Prepare for an Emissions Test
Passing a smog test means ensuring that the elements coming out of your exhaust pipe are within the stated range. You can follow some tips to adjust the chemical makeup of the exhaust materials and compensate for your vehicle’s shortcomings.
Test Your Warm Car on a Cool Day
For complete combustion to occur, your car’s engine needs to be warm. A warm engine produces fewer hydrocarbons through the exhaust. For accurate results, try to test your car on a cool day when the engine is hot. Vehicles taking in cool air runs more efficiently, and this can show on the smog test equipment.
Drive your car for like 20 minutes before getting to the station. You should make an appointment at the station to avoid waiting for too long before the test. The more you wait, you will have to turn the engine off, and cooling down before the test will affect the results.
Check this too: How Do You Clear a Service Engine Soon Light?
Use Fuel Additives
A fuel additive that you pour into your car’s gas tank is essential. The additive cleans any carbon deposits that are in your engine’s exhaust and intake paths. The air and fuel thus flow easily through the passages. This cleaning lowers the emission levels, improves combustion and the overall performance of your engine.
Inflate Your Tires Well
Ensure your tires have enough pressure, as advised by the manufacturer. If, for instance, your safe range is between 35 and 45 PSI, then fill your tires to the top of the safe range. Slightly higher tire pressure allows the engine to turn wheels with less effort, thus emitting cleaner gaseous waste.
Change Your Oil Before Test
If your oil has contaminants, it can cause higher emissions and make you fail the smog test. For that reason, ensure you constantly change your car’s oil for the best engine performance before the test. Your engine efficiency can change significantly after fresh oil change. Again, besides running efficiently, it will also produce less harmful gases.
Check Your Air Filter
Air should flow correctly into the engine through the air filter. But a clogged air filter can affect the emission test results. The filter hinders fresh air from getting into the machine, having incomplete combustion. Change the air filter before the test for a steady stream of fresh air into the engine. You will also enjoy an efficient engine with high performance.
Turn off the Check Engine light and Fix the Issue
Having a check engine light on will make you fail the emission test. Find a technician who can diagnose the reason why the light illuminates and fix it. You can also use other techniques to turn off the light, though they may last for a while.
- Drive your vehicle and let the light go off by itself
- Try to turn the car on and off three times to see if the lights will reset.
- Disconnect and reconnect the battery
- Use an OBD code reader
Pass emission test without catalytic converter
You can pass the emission test without the catalytic converter; if you manage to cheat OBD2 emissions check by using a special circuit or tool to modify the oxygen sensor readings, you are risking massive fines and an impound if discovered.
Some of the modifications can also go wrong and damage your ECU leading to the need for expensive repairs.
Moreover, some inspection protocols are rigorous and will manually check for the catalytic converter’s existence and signs of tampering to cheat OBD2 emissions.
Another way you can pass the test is if having an old car, one built before catalytic converters, were mandatory. For example, in the USA, the date is 1975. A vehicle manufactured around that moment will pass the emission test without a catalytic converter. But for modern cars, it’s a bit tricky to pass.
Another line of thought also suggests using a catless DP and pass an emission test if you have a tune. But remember to mention you require a test pipe file. The test will disable the O2 searching for a cat. It’s wise you also check your state emissions since disabling O2 will affect the readiness of the cat. Some states only limit just one system not ready and require all others to be ready.
How to Pass Emissions with a Modified Car?
Passing an emission test in some strict states like California is challenging for an ordinary car, leave alone a modified one. In such a situation, you require to follow some tips that will guide you to pass the test as follows;
- Make sure to follow the standard emission test preparations before you go for an emission test like mentioned above.
- Have your modifications done in a reputable shop, trustworthy shop that is aware of all the rules and regulations about emissions in your state.
- Buy local parts for modification as they have better quality
- Avoid altering the vehicle’s original emission system as it’s against the regulations and will make you fail the test.
What Causes a Car to Fail Emissions Test?
A car can fail the emission check due to the following;
- Illuminated check engine light which signals something is wrong with the vehicle
- Leaking gas cap
- After markets emission parts on the vehicle which are below the set standards
- A damaged catalytic converter that converts toxic gases to less harmful ones
- Faulty Oxygen sensor sends wrong readings to the ECU. It might just trigger the check engine light or increas the output of emissions and even damages the catalytic converter
What Happens if You Don’t Pass Emissions?
If you fail the emissions test, the DMV will not allow you to register your vehicle. That means you can’t get any legal plates to drive your car. When you fail, they will give you a complete report on the test and explain why you failed. That can help you figure out what went wrong and what you will do to fix it. After you make the necessary repairs, you can get a retest done for free in some areas.
Check this too: Check Engine FAQs And Troubleshooting Guide
Conclusion
As per the emission regulations, ensure your car has a clean bill of health. Car emissions should be less harmful to control atmospheric pollution. Always keep your vehicle in good condition, with uncontaminated oil, active catalytic converter, good air filters, etc. These measures will ensure your engine runs efficiently and make complete fuel combustion, thus less non-toxic emissions.