My car has Engine check ligh on when it idles, as soon as I gas it up a little it goes away. The motronic fault code is 1222 (oxygen control module). I replaced the oxygen sensor, swaped the computers and exhausts to see if it would make any difference, it didn't. The car has been tested by a few shops, they all agree that the catalytic needs to be replaced. Now my question is: What are my options here? 1) after-market untit 2) cut the catalytic and put straight pipes 3) get bmw oem catalytic