Hey guys! Looking to get some info on rear o2 sensors, and test pipes.

So I recently bought a Megan Racing header + test pipe for my 2003 MCS, and use it for local track days. Sadly they require no CEL to run on said track days, so my biggest concern is rear o2 code going off due to being catless.

So my question really is, Has anyone done a catless setup on their mini, and got around throwing rear o2 codes. Is there some tuner you can get to get rid of the code? Little extra info, the header + test pipe did come with a 90 degree o2 spacer.

 

The spacer is really the only thing that may work, there is really no electronic way around it, the ECU need to see a specific variance between the front and rear sensor period.

 

With that being said, how does the rear o2 operate? On my 07 wrx, the rear o2 controls long term and short term fuel trim based on the a/f, is the mini working this way? Or is it only checking for cat efficiency?

 

The rear oxygen sensor is a monitor for catalyst efficiency.

Nothing short of actually tuning the rear oxygen sensor out works, the simulators and spacers hardly ever get you 10 miles down the road without a CEL.

 

Thanks for the great info! I'll have to contact some local shops about more info on getting it tuned. Thank you!