Hello all,

I am a new Mini owner (about 2 weeks now) and the Mini Cooper S that I have has stainless steel headers that cause the CEL to ding on. I live in a state that requires inspection prior to registration of the vehicle and it won't pass inspection with the CEL on. I researched the issue online briefly and some sites recommended an O2 Simulator "Mini Cat" Catalytic Converter that attaches to the rear O2 sensor.... Any thoughts or recommendations on this issue??

Thank you

What are you currently running for front and rear O2 sensors and Catalytic Converter?

Honestly, and I know this sounds horrible, but I have no idea... I know very little about cars. I got this car from my dad b/c my old car broke and I was without a vehicle for 6 months. He bought this one used from a guy who apparently ran a race track for Mini's out of FLA, if that helps at all?? Is there somewhere on the vehicle I could look to find out and get that info for you?

yep, get under the car(safely on jacks) and follow the exhaust path. You should see the header, the first )2 sensor(pre-cat), the Cat, and then a second O2 sensor(post cat). If you don's see things in that order then that's what you need to fix. I run and OBX header which I believe comes with the O2 sensor bung(pre-cat), then a Random Technology Cat(excellent) that I had to have a post cat sensor bung welded on. I have no CEL's at all after two years. The CEL's usually come on because the sytem is designed to measure the diffference between the measurements of the pre and post cat. What is your CEL fault code? If you don't have a scanning tool you can go to Autozone or similar place and they will read it for you and give you the actual code number which can further help us diagnose your issue. Good luck.

Are you assuming that it is the header that is causing the problem?

I agree that you need to get the code read and then go from there. It may have absolutely nothing to do with the header.

Even if you run a o2 simulator....
Your car will fail the visual part of the inspection with no cat....most states LOOK for the shape of a cat AND no light, along with the usual light, tire and brake checks....
If you want to keep the header...
You could buy a cat...have it welded in....and then run an o2 simulator if you still get a code ...some highflow/aftermarket cats can be tricky to keep light free...
If you are not crazy about the he extra sound of the header....
Buy a used OEM one for about $150-200....has the factory precat and cat welded to it...and bolt it up....
One tip...non OEM brand o2 sensors can give some folks issues...so if you need to buy one....get the right one...not the cheap universal...it will end up in the trash...

P.S.
Using a formally tracked mini on the street can get very $$$ repair wise... If you could not afford the fix the old car....hate to see the bills for a used track car used as a daily driver...
Just need to think about it!! Good luck.