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Nagging yellow check engine light on 2002 subaru forester

This is my first subaru I love the car…besides this nagging yellow light…my finace has a 2004 subaru outback L.L. Bean edition and he has never had his check engine light go on.

My check engine light is on more than it is off. I panicked when it first happened and brought it back to the dealer and they cleaned a few wires and it went off for a week or so then came back on again. I have a few friends who own subarus and their check engine lights are on all the time too…someone told me it is a moisture problem…something gets wet in the engine and until it dries…the light stays on.



to my fellow forester drivers…do you guys have the same problem?

No Forester but, I did have with an older Subaru. Each time it did come on, I disconnected the negative battery terminal for a few moments, then reconnected. If it stayed off, fine. If not, a trip to the mechanic was in order unless I felt like repeating it. It was usually a once a year deal after five years of age and often had a legit cause. O2 sensor was somehow, quite prone to a rusting mount, the usual culprit. Because I was too cheap to replace the converter, a spot weld worked every two years til I sold it.

This is not special to Subarus. Computers in all modern cars control and monitor many of the car’s systems and report when there are things going on that are out of spec. They are not to be ignored.

The next time the light comes on drive into and autoparts store (big chains such as Autozone or Advance are your best bet), and ask them to pull your codes. Write down the exact code (something like P0123) - not what anyone says about it. If someone tries to sell you something, politely say that you’d rather be sure first since you’ve heard all of these codes require more diagnostic work.

Post the codes here along with as much info as you can muster about the vehicle’s maintenance history, recent repairs, and whether or not is is behaving strangely.

FIRST you need to know what the CEL code is. Around here, AutoZone and a couple of other autoparts places will read the codes for free. A friend of mine had the Knock Sensor go bad on his 2001 Forester. It turns out to be a common failure and pretty easy and cheap to replace your self.
But don’t just guess, find out. It may be something you can ignore, but it may not be. The Knock Sensor is vital and if you drive with it not working you can damage the engine. It can also be other sensors that keep your car running smooth.
SO go get the codes read at AutoZone, then you can probably figure out what to do next.

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 (like P0123) not just their translation into English and post it back here.

Regarding warning lights:

  1. if the coolant temp light comes on, shut off the engine ASAP

  2. if the oil warning light comes on, shut off the engine ASAP

  3. if a FLASHING MIL/CEL comes on, shut off the engine ASAP

    ASAP means driving to the berm of the highway right now and not waiting for the next exit.

But if the MIL/CEL is not flashing, then it’s not an urgent indicator.