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Q: Check engine light on again

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I have a 2006 gmc truck that has been regularly maintained. I replaced the mass air flow filter last Dec., was smogged in Sept.(passed) and 3 days ago replaced the cannister purge valve now the engine light is on again is this a problem in gmc trucks? What is the worst thing that can happen if the light stays on or continues to have problems with the evap system??

My car has 70000 miles.
My car has an automatic transmission.

A: Your check engine light may come on for man...

Your check engine light may come on for many different reasons such as a faulty mass air flow sensor, a faulty O2 sensor, a bad catalytic converter, bad spark plugs or wires and many other reasons. Unfortunately due to the wide range of possibilities for the check engine light to come on, the best way to narrow down the scope of what may be causing this is to have the vehicle hooked up to a scanning tool to download any potential fault codes that may have registered in the computer. The disadvantage to not having this looked at or diagnosed to determine what is causing the light to come on is that because it can come on for so many different things, you may not know what exactly it is coming on for which may mean something very serious or something not as serious. For this reason, it is always best to at least have it diagnosed to determine what is causing it to come on. I would recommend having an expert from YourMechanic come to your location to take a look at your vehicle to determine what may be causing your check engine light to come on.

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