Just changed out the upper O2 sensors. Easy access. The Bosch electrical connectors were a little different than the OEM so it was a tight fit getting them on. Seems Bosch didn't cut the interlocking groves on the sides as the OEM sensor. I used sparkplug boot grease to make the gasket material slip in easier.

Had a code E10 showing before the change (O2 sensor, bank 1). Now to see what the wife says after driving it. I'll check the codes again tomorrow to see if it went away.

Thanks for the write up!.

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2003 X5 Steel Grey
3.0i e53