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Emission important is it to get this taken care of

I have an 07 Impala. Just recently, the engine light came on. I contacted OnStar who did a vehicle diagnostic and told me the problem was the emission control and further told me I should tighten my gas cap which might take care of the problem. It didn’t. How important is it to take care of this?

If OnStar told you to try and tighten the gas cap it indicates that there’s a leak in the EVAP system. The EVAP system collects and stores fuel vapors so that they can be burned off in the engine. If tightening the gas cap didn’t turn off the light then there’s still a leak somewhere in the EVAP system.

A leak in the EVAP system won’t have an effect on the operation of the engine. However, with the Check Engine light being on constantly you will never know if another more serious problem may arise that would turn on the Check Engine light and possibly do engine damage.

So it’s better to have this problem corrected so if there’s future issues with the emissions system you’ll know because the Check Engine light will come on.


Thanks Tester; what does something like this cost to fix on average?

If you live in a state that does periodic emissions testing, you will be unable to pass the state inspection process until this is taken care of. Additionally, in some cases, you will run into problems with fueling the car when there is a problem with the EVAP system.

The cost could range anywhere from…less than $100…to…perhaps the $400 range.