Help! I have an 05 S and it's O2 sensor is on the way out. Really hard start. How tough are they to replace? When I look up sensors on line I see a range of $50 to $400 - any suggestions? Clueless here. (I have 175,000 miles on Jack Jack)

Vicki

 

I'd NOT blindly throw an O2 sensor just cause "it's hard to start"
Does it have a CEL ? Is there any codes ? Describe hard to start ?
Might just be a weak/bad battery

 

I THOUGHT my '03's o2 sensors were going when a SES light came up....turned out to be a purge valve issue. I WAS going to try and CLEAN the o2 sensors using what the BMW forums suggest: CRC QD Electronic Cleaner. The BMW people SWEAR by the stuff and i did use it on my purge valve to clean it out. So far, so good.

I would start on some other places for hard starts though. Per Bad Venge: battery...spark plugs perhaps? Injectors?

Good luck with that.

-OG

 

The dealer has informed me it's the knock sensor that's not operating properly. $1050!