1998 Subaru Legacy Check engine light

Hello,

Go by your local auto parts store and have them pull codes for you and post them here.

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There are several houdred things that can make your check engine light come on, most of them can are emission control related. Something as simple as a loose fuel cap can make your check engine light come on on late model vehicles. The first step in the diagnosis would be to find out what fault code turned on your check engine light.
There are serveral large chain parts store that will read the codes for you free of charge. As I stated earlier, knowing the code is the first step in the diagnosis. Once you know the code, there is a standardized diagnostic flow chart for each code. An oxygen sensor code (there are several) does not nessisarily mean you have a faulty oxygen sensor, the sensor may just be what senseced the problem.
Once you know the code, let me know & I'll do my best to help.
Dan

Your mechanic is correct, topping off the tank will force raw fuel into the evaporitive system. Raw fuel in the evap system can set a check engine light on some vehicles and will eventually damage the evap system on all vehicles. It is best to fill the tank only untill the fuel nozzle clicks off the first time.

Glad you have it figured out. Still wouldn't be a bad idea to have your computer scanned next time it comes on. There are hundreds of codes that can set your check engine light. As I stated earlier, most large auto parts chains have a program where they will read the codes for free.

Once again, I am happy you were able to take care of it.

Thank you,

Dan