I was running the Buschur T-Back (catless) /w race muffler. I recently switched out the straight pipe for a hi-Flow Cat and the BR race muffler for the Magnaflow.

I reset the Ecu and within a day I had the Cel again. I reset once more, and had the Cel return after about an hour worth of driving. Took the car to AutoZone and got the code pulled.

P0139... Bank 1, Sensor 2. o2 sensor slow circuit response (Or something close to that)

I pulled the sensor out, and took a toothpick to the small hole that is drilled into the o2 sensor Bung, on the exhaust pipe, and also in the small hole that is at the end of the Bung (inside, at the exhaust pipe)

I was thinking, maybe I had some buildup in the holes, and that was causing the problems. I reset the ECU, drove the car about 2 hours. At the stop light right before my home, the F'ing light comes back on....

Anyone have any ideas? Did I fry the 02 sensor or something?
Has anybody here fixed this problem....

 

The sensor itself is likely fouled....If there was any build-up in the hole, I would suspect it at least. Since the sensor itself is located behind the hole, as I understand.

SC~

 

So.... buy a new sensor? >=/


Thanks SC =)

 

We are working on the 02 simulators again for the EVO. This car is a complete PITA getting around that rear 02. Not sure which highflow you are running, I am going to assume ours.

I will keep you guys posted to the outcome of the simulators.

David Buschur
www.buschurracing.com

 

Oh, I see the problem. You are using the 02 bung that was designed for the offroad pipe. You will get a slow to respond light.

That special bung was built to limit the amount of exhaust the sensor would see with an offroad pipe. Now you have a cat in there and using the same bung, it won't work. Simple solution, get as big a drill bit that you can and run it through to open up the hole in the actual exhaust pipe, this will give the 02 sensor more exhaust flow and should take care of the problem.

David

 

Hey David, have you guys tried the O2 sensor elininator from summit? SuperchargedGTZ said he tried one and it worked. I was part of a Beta test group for Kastle's Korner for an O2 Eliminator and I got the 0139 with it, so if you need a beta tester my wires have already been cut and respliced so I will do it again. That damn CEL is driving me up the wall......

 

Thanks David!