Hey gang. I need some advice on the exhaust conversion of a '95 M635csi. A previous owner re-installed the european exhaust (resonator-pipe-muffler; no oxegen sensor) after the car had been federalized. However, the car will not pass inspection in my state (PA) when the emissions test becomes mandatory next year. As a result, I need to install a cat.
An acquintance of mine in a similar situation has done some investigation and determined the the original federalization included the cat, an oxegen sensor, and a control module to adjust the air-fuel. Foregoing the sensor/module risks clogging the cat in a few years, necessitating replacment. However, the modules are difficult to find. If I go the no sensor/module route I could conceiveably make the cat "swappable" and install it only for inspections.
Does anyone here have any experience with this situation so they can lay some wisdom on me? Since the driveline is the same (to a degree) as euro E28's, I was hoping someone could help me out. Thanks.