Hi everyone! About 2 years ago I removed my catalytic converter from my mini, and installed a header and cat delete pipe. I had the car tuned and used the vibrant j bend defouler with the middle sized bung. This worked for about a year, but recently I got the code p2096 for post cat sensor too lean. I replaced the sensor and have the same code. Any ideas? Also, my car runs very rich, so I’m curious if it’s compensating for the code or not. Does the post sensor affect fuel trim? P.S. I removed the cat because where I live it is no longer required, and it was failing anyways. Thanks!

 

The conventional wisdom is that the pre-cat sensor takes care of fuel trim and the post-cat sensor only monitors the health of the cat. But there are instances where the DME will make adjustments to fuel trim if it doesn't like the readings it's seeing from the post-cat sensor.
Why it took a year to start having problems? IDK. Maybe try a longer defouler.

 

Thanks For the input! I've been reading a lot online that this code may be caused by the o2 sensor not getting hot enough. I tried the steel wool method to try and insulate the sensor more to get it hotter, but unfortunately the code came back. I think i may try doing the capacitor and resistor trick to try and smooth out the signal from the post sensor. Wish me luck!