Skip the auto shop - Our mechanics make house calls

Q: Check engine light on again

asked by on

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.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Misfire caused bad o2 sensor?

As you may know the oxygen sensors which are part of your emissions system read exhaust gases to determine whether or not the appropriate amount of oxygen is present in the exhaust. Based upon this reading, this information is relayed...

Q: What else can be done

You should have an engine compression test done to see if one or more cylinders are low on compression. If the spark plug insert is not installed correctly or leaking compression it will be identified in this test. If the...

Q: Engine misfiring 2003 Honda CR-V

Misfires can be caused by several things. I would first check for vacuum leaks, then I would pull the plugs to see if they need replacing. It is possible that have a fuel system concern, but I would lean more...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.