These photos are of the drivers side (USA) post-cat O2 sensor, but all four sensors attach the same way. The only exception is the pre-cat O2's wire is not held to the body by the metal clips.
Get your car on ramps/jackstands/a lift: (Ken edit)
That's all there is to it really. Good luck!
@TMcNasty - Just replaced my O2 sensors (pre and post) using your directions. Worked beautifully, and I found it easier to break free the sensors with the beast up on a lift, vice on jacks. I just couldn't get the proper leverage. THANKS AGAIN - I've saved your directions for the next time. Cheers!
Arg...glad it worked easily. The hardest part of this job imho is coughing up the $ for the parts. Yeah a lift makes removal much easier I'm sure, but luckily with a little patience and tweaking of breaker bar positioning it can be done on ramps.
Extremely easy DIY. I'd rate this at like 1/10 difficulty level. Took me about 15 mins to remove both, including time to jack up car and place jackstands. Installation took another 15 minutes. My INDY quoted me $340 OTD.
I ordered my Bosch 13477 (Pre-Cat) from Amazon for $53.03/each. They do come with anti-seize putty already on the threads.
I did it with a jack and jackstands. One side at a time. Tools used were a big 22mm open-ended wrench, hammer, and a 10mm socket. I would say 2-3 taps of the hammer loosens the O2 enough to unscrew by hand.
Extremely easy DIY. I'd rate this at like 1/10 difficulty level. Took me about 15 mins to remove both, including
time to jack up car and place jackstands. Installation took another 15 minutes. My INDY quoted me $340 OTD.
I ordered my Bosch 13477 (Pre-Cat) from Amazon for $53.03/each. They do come with anti-seize putty already on the threads.
I did it with a jack and jackstands. One side at a time. Tools used were a big 22mm open-ended wrench, hammer, and a 10mm socket.
I would say 2-3 taps of the hammer loosens the O2 enough to unscrew by hand.
Good to hear that it went easily. Judging by the heavy soot on the senor bulbs, I thought I'd raise the question of
your thermostat not regulating to the minimum 79 degree C. It sure appears to be running excessively rich.
Either that or possible cracks around the O2 sensor bungs.
What temps are you seeing at freeway speed with Test #7 (KTEMP) displayed?
Good to hear that it went easily. Judging by the heavy soot on the senor bulbs, I thought I'd raise the question of
your thermostat not regulating to the minimum 79 degree C. It sure appears to be running excessively rich.
Either that or possible cracks around the O2 sensor bungs.
What temps are you seeing at freeway speed with Test #7 (KTEMP) displayed?
Just a thought,
Alan
Alan-
Good observation. O2 sensor bungs are brand new as its on my brand new SS header connector pipes. I will check this tomorrow and report back what readings I get for #7. Hope it hits that 79 temperature.
This is one of the first things I will be changing when my car arrives from Cali. It looks very simple, esp with a lift. But damn these sensors are expensive. I thought $35 for my Jag was high. I am looking at over $300 for all four from Bimmmerzone. Are the post cats just as important as the pre cats to change?
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Yeah a lift makes removal much easier I'm sure, but luckily with a little patience and tweaking of breaker bar positioning it can be done on ramps.
BMW CCA NJ #416647 
The Other Stable: 
Linear Mode
