CEL light goes on and off from day to day!

[JimmyJ]

I have a '02 wrx with a rebuilt motor and a 2.5" catback exhaust. I went to advance auto today check it and it wouldnt give out a reading. Could it be a fuse of some sort maybe? The car runs fine so I'm thinking its something small, hopefully. I'm gonna try an disconnect the battery for a while and see what that does...

[baller_v24]

Try Auto Zone. Get the code read when you actually have the CEL on. It wouldn't hurt to check all your fuses to include the ones behind that little tray on the left of steering wheel and in the engine bay.

[wagonracer]

Does it flash when it comes on ?

A flashing misfire CEL will not leave a readable code. Those are the only CEL's I've ever experienced that go away on their own. I would try to get it read while it's lit. Leave the car running when they hook up the code reader.

[pzr2874]

I thought the ECU stores all the codes that are thrown ? Ron corrected me on this a while back.

[nagyhead]

the ecu will store the codes, what kind of scanner where they using?

[JimmyJ]

Originally Posted by nagyhead

the ecu will store the codes, what kind of scanner where they using?

Not sure what kind of scanner they were using but it didn't work. What did work though was disconnecting the battery. Didnt I'll give it another day and see how it goes.....

[JimmyJ]

Originally Posted by wagonracer

Does it flash when it comes on ?

A flashing misfire CEL will not leave a readable code. Those are the only CEL's I've ever experienced that go away on their own. I would try to get it read while it's lit. Leave the car running when they hook up the code reader.

I'll make sure they leave the car runing next time I get it checked, the cel doesn't flash at all. Its kinda like when I go to work in the morning its on, when I go to lunch its off. Its been like that from day to day for the past 2 weeks.....

[pzr2874]

The codes are in there.... Get someone with a COBB AP if you can't find anything else.