Mechanics

SERVICE ENGINE SOON LIGHT

2004 Pontiac Grand Am • 6 cylinder 2WD Automatic • 75,000 miles

As per the owners manual it is affiliated with air in the gas tank, so I re close the cap, twisting it 3 times as recommended, and it normally goes away in 24 hours, well its been back 3 times this week, do I replace the gas cap or could it be the gas sensor? Happy Holidays
Lisa
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Lizzie47
December 26, 2013.




Fumes in the fuel tank are only one of about 300 different reasons that light can come on.

The "check engine" light is an indicator for a system that monitors many electronic functions in the system, also called the "malfunction indicator lamp" (MIL). It can come on for any of hundreds of different causes from any of the systems that the computer monitors. Some are very important and can lead to further component or engine damage and some are emissions related not as serious but still a problem and need to be repaired.

Your first step is to have the computer scanned to retrieve the trouble codes that were set when the check engine light came on. Those codes will give you specific information about what the computer saw and will get you pointed in the right direction to find your problem. With a 1996 or newer and some 95 cars and you have an AutoZone or Advanced auto parts in your area, they will read them for free. Once you have these code numbers, we can be a lot more specific about what your problem may be.

Wrenchtech
Dec 26, 2013.


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