Check engine light, 99 Subaru Forrester

the check engine light has been on for months. at first, we took it in and had the computer check-ok. they cleared the codes, light came back on. we had the the purge valve replaced- the evap. component may have failed, light still on. had the system smoked, mechanic unsure as to were the leak was. spend lots of money and the problem hasnt been fixed, but car is driving fine. any suggestions?

Sure. Can you give us the trouble code that pops up? It would be very helpful to know exactly what the fault is. All cars from 1996 and up use computers that monitor not only the engine functions, but the engine’s emissions. An emissions failure will trip the CEL, but not interfere with normal engine functions. By the sounds of some of the repairs, that is probably what you have. I’m also guessing you do not have emission testing in your locale. Here in Atlanta, the state will not renew the annual car tag with the CEL on.

That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code not just their translation into English and post it back here.

The most common source of this kind of trouble is the gas cap. I assume that has been replaced already in an effort to fix this problem. I would go to another shop to have this fixed. It appears the one you have been going to can’t help you for some reason. A vacuum leak in the fuel system shouldn’t be too difficult to track down.

thank you for your response. the car has been running fine and the light has been on for 6 months. the dealer wants $100 to just tell me whats wrong and my other mechanic could not figure it out, but thought it was something with the emissions and said you had to take apart the whole underside to find where the emissions were leaking from. is this bad on the air quality to be driving around with leaking emissions? does it affect the gas mileage? is it something i can just ignore? the mechanic did not tell me the code.
thanks, kirsten

i will try that, the dealer wants $100 just to tell me that info.

Actually the $100 is for a diagnosis of the problem based on the dealers experience and access to knowledge base. So posting codes may just direct you possibly to one of many fixes. The $100 charged is the more than likely answer that will fix the issue. Many garages will waive this fee or incorporated at a discount into the repair of an item if all done at the same time.

Some people waste garages time asking for free diagnosis and then repairing the items themselves, hence the warranted diagnostic fee.