Hi all,

A local repair shop diagnosis indicated a faulty O2 sensor on my 89 535. I bought the sensor, and while i was taking a look at the exhaust system i relaized that there seems to be another sensor right behind the Catalyst.....hmmm. I thought they only had one sensor there..i hope someone knows about it. one more thing is the message i get whenever i start the engine "CATALYST.....OWNER'S MANUAL"...the local dealer confirmed that it is caused by a bad O2 sensor, but with two of them now....i am a bit confused.

Thanks for your help.