So, can you pass an emissions test if the check engine light is on? The short answer is no, you can’t.
But you can try to turn off that check engine light, and if possible, find out what’s wrong and why the light came up in the first place.
In this article, we’ll show you one way to do that.
Besides this website, you can also watch videos on our YouTube channel, where we have many car-related videos that may help with maintenance, driving, etc.
CAN YOU PASS AN EMISSIONS TEST WITH THE CHECK ENGINE LIGHT ON?
DISCLAIMER
We would just like to outline that this method is applicable only if there’s a minor temporary problem with the car or a system glitch that activated the check engine light.
If there’s a bigger issue with the engine, exhaust system, or else, you’ll have to solve that problem first. In that case, this video will probably not help.
WHAT WILL YOU NEED?
To turn off the check engine light, you’ll need an OBD tool, one that can both read and erase the error codes.
You can buy a cheap OBD tool; it’s widely available for a couple of dozen Euros or Dollars. If you want to buy a more expensive one, all the better.
In both cases, it is a good future investment.
If you want to learn more about how to use an OBD tool, click here.
HOW TO CLEAR THE CHECK ENGINE LIGHT?
The first thing you should do is connect the tool to the OBD port on your car.
Next, find the scan option and let the tool scan for any errors. Since the check engine light is on, there will be error codes for sure.
Once the scan is done, the important part comes. That is to see the error codes and conclude what they mean.
In case you have an error code regarding the exhaust system, like for a bad catalytic converter or a bad lambda sensor, try turning off the check engine light.
Lots of times these errors appear temporarily and are due to things like bad fuel quality, an air leak, or else.
Especially do this if the light appears here and there, with long intervals in between. There’s even a good chance that you may solve the problem completely this way.
Once you’ve turned off the check engine light, it’s best to take the car for a spin, make a couple of dozen kilometers or miles, heat the engine up, and see if the light comes back.
If it doesn’t, you’ve perhaps solved the problem, but if it returns, you’re going to have to make some sort of inspection and repair.
Also know this, if you get an error code for a more serious problem regarding the engine and its systems, best not to take the emissions test until you solve it.
If you ignore this, be sure you will not pass the test.
CONCLUSION
This method of trying to pass an emissions test is especially worth going through if you drive an older or high-mileage car.
Oftentimes, these cars have lots of costly problems. A good example is an old catalytic converter.
In this case, if you had to buy a new converter, it would probably be worth half the value of the whole car.
So, there’s not much logic in replacing it, and the next best thing is to try and turn off the check engine light and hope for the best.
Also, be sure to do this if you have fuel quality issues in your country. Bad fuel will trigger an intermittent check engine light for sure.
Written by: Sibin Spasojevic
Former car technician, life-long car and DIY enthusiast, author for Despairrepair.com
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