There are several O2 sensors, do you happen to have the Codes from the dealer? That would point to the bad sensor. If your considering changing it yourself, the sensor itself only cost around 50 bucks but requires a spark plug boot removal tool that you can pick up for around 20 bucks.

__________________


'66 250S (SOLD)
'72 250C (SOLD)
'92 190E 2.3 (SOLD)
'02 C320 Wagon (SOLD)
'04 S40 (SOLD)
'99 535i (Euro Spec)