LS1Z2800

Hello everyone I'm new to this board and have a question that maybe I can get some help with here:

I have a '00 Z28 A4 with some bolt-ons, Y3000 stall, borla exhaust & lid. Lately I've been getting an "SES" light, and would reset it myself. This would last for about two months before it would pop up again. Now it seems as if I'm having to reset it every other day now. I finally sent it to a shop to be diagnosed, and according to their equipment it was signaling that my catalytic converter was the culprit.

Afterwards, I took the car to a local muffler shop, and was informed that if was my "cats" it probably was due to running "supreme" fuel which I've done religiously since day one.

What do you guys think about this? By the way my car now has over 113,000 miles on the odometer.

GM Muscle

iTrader: (9)

You should really get the actual code. Start by looking for any exhaust leaks around the manifolds and cats. I have a small leak and it will trip a P0430 "catalatic efficiency below Threashold" code. Happens anywhere from once a week to once a month.

BTW: I just saw the amount of miles on your car. It's possible the O2 sensors are getting weak and the outputs between the front and rear sensors are varying making the car think it has a bad cat. Does the car run normal?

LS1Z2800

Thanks for the info. Yeah, my car runs normal, seems to run as strong as ever. I'll take yor advice, and do a follow up with the O2 sensors as well.

HumpinSS

iTrader: (1)

Change those 02 sensors. Mine have been in the car for 60k and when i replaced them it was a night and day difference.

even if this isnt the problem it will still help with power and fuel economy

69_YENKO

iTrader: (16)

doesnt it say on the inside of the gas fill door that preimum/"supreme" fuel is recominded. I think regular fuel would clog them up faster.

I pulled that same code "po430", it was the cats. I had them replaced under warranty.