Hi everyone, i have a 2002 mini cooper s and i have been trying to find a way to get the p2096 engine light to turn off. My car emission exempt, i just want the code to be gone. My car has no cats, and i have made a circuit that basically can filter the post o2 sensor signal to smooth it out, and essentially hold it around .7-.8v. the problem is, no matter what i do, i keep getting a p2096. i even set it up to where it would read a perfectly constant .9v at ALL times. I expected to get a rich code, but nope, p2096 again. WHat am i missing here? isnt the p2096 completely dependant on the voltage of the post sensor? i thought a value below .5v would indicate a too lean code. Please im really stuck here, i need some o2 sensor pros for some help here! thanks! Also i'd like to note, i have the sensor directly in the exhaust stream, no defouler.

 

I'm pretty sure the post-cat o2 voltage is supposed to fluctuate slightly along with the pre-cat o2. Any chance the computer is picking up on that difference and throwing a code?

 

Your correct, My softwares main purpose is to basically read the real time signal from the downstream o2 sensor, and adjust it to what the ecu wants to see. To put it somewhat simply, the software lets the sensor send its live data to the ecu, but once it detects a large fluctuation, it triggers another script that basically puts a holding limit on the signal, so it is only able to bounce however much i decide. in the photo i posted, i told the software to just output a steady .9v to simulate a rich condition, which SHOULD have thrown a rich code, but i got the lean code anyways. After some more searching, i saw some people saying you need to reset the adaptions for the engine. I have the INPA software with a obd-usb, so i reset the adaptions, reset my software to simulate a post cat o2 again, and boom, no more code. I spent about 8 hours today getting the same code OVER AND OVER just because of the ecu's adaption values had compensated for my p2096 that was present for over a year.

 

02 sensor outputs can differ depending on the type of sensor. My understanding is that most post-cat sensors are of the variety that 450mV output is stoichiometric, above that is rich, below that is lean.
With a properly functioning cat, the output will be constant. Any significant fluctuation indicates a bad cat.