[be-em-veh-808]

Just finished the O2 sensor change job for my 2007 E91.

What: changed the Bank 1 Sensor 1 O2 sensor Part # 11787558055

Why: SES light came on --- lived with it for past 4 or 5 months, finally got around to replacing

How much: ~ $150 with shipping from AZ Autohaus --- note: there are write ups around for replacing with a 'generic' Bosch sensor head ( < $100) --- but that requires saving the harness/plug end of existing old sensor and splicing/connecting to new sensor head/tip --- too much work for me.

How:
Fairly straightforward job that took me 2 hrs from opening the hood to shutting the hood.
Removing the air filter and all the plastic cladding as usual --- took me ~ 30 min.
Removing the existing sensor and replacing with new took me ~ 45 min. Replacing the plastic cladding and air filter took another 20 min. Then I spent some time cleaning up the engine bay --- vacuumed with a wet/dry vac.

Start by using a OBD2 reader and erase the error code P0030 before starting the job.

I used a 18 in breaker bar, 6 inch extension and a offset type O2 sensor wrench.

Tip: tape the O2 sensor wrench to the extension --- ensure nothing falls into engine bay black hole.

Breaker bar made removal of existing sensor a cinch. Then, I replaced the electrical connector side of the sensor with new sensor (NOTE, you should start at the O2 sensor tip instead --- I'll explain later).
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I traced removed the wire of existing sensor that I removed --- starting from the electrical connector end --- following to each wire holder and removing/replacing until I got to the O2 sensor tip. Well guess what? This makes screwing in the O2 sensor into the engine more difficult --- since the wire cannot turn --- or wire would need to twist.

Luckily I was able to make a few twists and tighten the sensor head. there are several rotation/twists on the wire. I hope that does not cause issues or reduce the life of the O2 sensor.

That was all there was to it. I was lucky that P0030 was due to malfunction of the Bank1 Sensor 1 (Cylinders 1-3, precat). This one is easiest to reach.

Anyways --- if anyone has Qs, please post here or PM me. I did not take pix --- sorry.

Glad the job went smoothly --- well, I shall see in a few weeks of driving if any issues arise or come back.

Glad I saved ~ $200 labor that the Stealership would have charged -- at least. Or ~ $150 from an indy.