I have a 04 325I. How many O2 sensors does it have? About how much will if cost to replace any of them? Thanks, GF Hoffman
This would be a better This would be a better question for the E46 model topic; I believe chapter-related events, etc, are more likely to be discussed here. I don't know offhand if E46's have two or one, but you can check realoem.com for your car and you should find O2 sensors listed in the appropriate area.
You have four. An M54B25 (the engine in your car) has four oxygen sensors. There is a pair in each cylinder bank, one upstream and one downstream of each catalytic converter. You can see the upstream ones on top of the exhaust manifolds, looking down alongside the engine on the right side of the car. The other two are underneath the car, just aft of the cats. The sensors cost about $150 each. I've no idea of the labor costs because I have always replaced them myself.