2002 R53, 245K miles, blew the engine on the track. I found a used engine with low miles and swapped it in. Basically just the block and head went in with all the ancillary stuff from my original 245K mile engine. I replaced some stuff, relubed the SC and everything went well. Fired up and drove for a while, and then got the P2096 code. I just replaced both O2 sensors (with the correct NGK) and R&R'd the fuel filter. Runs super smooth, but just won't idle when hot. Super smooth when cold. Any ideas? I think I have to go to the dealer for the P2096. I've read a bunch on that and it's a frustrating one.

 

get ahold of inpa and factory reset fuel and throttle adaptions. That stupid debunked dash button press reset doesnt do anything other than the gauges. So either find a quality scan tool no idea on model as I just went to ista and inpa as I am a tech.

 

Could try this never done it myself or know if it does squat as again insta or inpa lol

https://www.precisionecu.com/blogs/e...i-step-by-step

 

I had this issue with my car. It ended up being a defective primary o2 sensor. It can also be a vacuum leak - check plastic intake pipe in-between supercharger and throttle body, clogged cat, or a cracked exhaust header - usually at the 1st cat on the stock header if your motor mounts have failed.

You also need to reset the adaptations. I used INPA, but a OBD2 reader with more advanced abilities can do it too.

 

I had a very similar code (P2097, '04 R50) appear ~14 months ago and the dealer by me wanted ~$220 to reset adaptations but I google searched bmw/mini specialist and found someone to reset my fuel adaptions for ~$68. I did it 2 months ago and it worked. Another option to consider.

 

Good news. While procrastinating getting the INPA software, I kept driving and eventually the idle became normal. About a month later, the SES light went off on its own. I suspect one of the O2 sensors was bad, since I had a lot of miles on it, and the ECU finally figured things out.