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.

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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Car shakes and vibrates

A concern like this can be produced by a number of different things. Such as; a large vacuum leak in the intake system, lack of airflow to the intake system, lack of fuel delivery caused by a failing fuel pump,...

Q: Warning lights stay on and wipers and lights won't work 2009 GMC Canyon

Hello. From my experience with this vehicle most of the time this is caused by a failing ignition switch. When the switch fails internally this occurs. I usually do a voltage drop test of the switch to determine if it...

Q: My Check Engine Light came on and reads the code P0108. What is the problem?

Hello. The code P0108 means the manifold absolute pressure (MAP) circuit is detecting a high input voltage. The PCM and MAP sensor communicate through a 5 volt wire that changes voltages as the sensor's reading changes. When the sensor detects...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...