I've really enjoyed reading all the info here at clubwrx and would appreciate some more info if anybody has any idea about this one.
I've had my 02 WRX for about a month now it has 46K on the odo and is stock. (At least I've never done anything to it). The car runs great and doesn't seem to be having any driveability issues.
The first time I take it up to 105MPH- the CEL comes on. Having the car such a short time I take it back to place where I bought it from (should have just gone staight to Subaru) The tech pulls the code and it is P1131- but, get this ,the service writer comes back and says "whatever it is it's not under warranty because the code was thrown at over a 100 MPH" When I ask why is that? he says " these cars arent meant to go that fast" OMG , my reply was "yeah, right". So after some complaining they cleared the code and said it might need a new ECU if the same code comes on again. I don't really want to believe them because they are a used dealer and I don't think they have the resources to know.
Needless to say I'm done going there. So I drive around for a week before vacation with no problems never going over a 100. But not able to recreate the CEL.
Until, I take a road trip to L.A and I have to see if this code will come up again- so up to 100 , no CEL, no CEL, until 125MPH the CEL came on. While down in LA I have the codes scanned and cleared at an Autozone or similar store. Both P1131. I had to have them cleared because i'm afraid that even if it was covered under some emissions warranty the at SOA won't cover it at that speed. After a few gas stops the was the CEL light would turn off. And the only time I've been able to get the P1131 code under a hundred was going uphill in 4th at about 80 MPH. Like I said the light goes off after a few cycles and it's not going into limp home mode or anything like that.
The research I've done tells me that it's the front 02 sensor short circuit or something like that-a tech friend of mine used some of his resources at work at said that it was probablly just an emissions parameter being to sensitive. And the only similar stories I've read here had to do with gutted up-pipes. I don't count this out because i'm the second owner, but from inspecting the car it doesnt look like tools have been on anything ( it still has the whit toothpaste and blue dye intact on the threads).
So I'm getting a P1131 when I drive fast. The first time it came on at 100, the second time at 125, did it have to adapt because it never had been driven that fast? I don't know. I'm anxious to hear some opinions on this because I've just ordered the ecu , and the ECU won't accept a reflash if there is something mechanicly wrong with the ECU. What do I think is wrong? I think this is an 02 California car and that the cars ecu was tuned to meet emissions and when it read slightly out of spec it throws this code. Do you think this ecu is going to work? Thanks in advance.