Is this a simple rear 02 sensor replacement or should I dig a little deeper? Nothing wrong with the car's performance and at idle. Has anyone experienced these two codes before? Should I go with OE or aftermarket direct fit sensor?

Thanks!

 

I just failed an emissions test here in Massachusetts with those same 2 codes, P0137 and P2270. The garage wasn't much help in diagnosing or even pointing me in the right direction, and I am not experiencing any physical problems with my 02 Mini. If you have had any luck in getting an answer anywhere, your experience would be appreciated. I will probably start with replacement of the 02 sensors without any other direction.

 

Wow....there are real people on this forum. I couldnt find an exhaust leak or vac leak. I changed out the rear 02 sensor so Im waiting to see if the codes pop up again. Before I did the 02 swap, I only got error code P2270 the second time around. I will let u know what happens.

 

The 2270 is rear. Have u changed ur header out? Mods?

 

Stock 04 R53 58k miles. Swapped out the rear 02 sensor and so far so good. No codes popped up all of last week. I would first look for any vac leaks and exhaust leaks. If those check out then its more than likely a bad rear 02 sensor.

 

02 sensor (rear) if you have a OBII reader you can reset it. I got my 02 sensor from advance a year ago or so not aftermarket, it was $168 or so.