BimmerFest BMW Forum banner
1 - 7 of 7 Posts

·
Registered
Joined
·
71 Posts
Discussion Starter · #1 ·
I scanned and got these codes; p0155 is saying oxygen sensor heater ciruit bank 2 sensor 1. Should I replace both O2 sensors or would I have to do more ?
 

·
Registered
Joined
·
1,219 Posts
Replace both pre-cat sensors.
 

·
Registered
Joined
·
1,739 Posts
I am going to have to disagree but it is your choice.

The failure of the heater on Bank 2, Sensor 1 means you only have to replace that O2 sensor since the heater on the Bank 1 sensor is still OK. The heater only works to help the O2 sensor heat up quicker so the ECU can go to closed loop quicker during the first few minutes after a cold start. The heater shuts off after that.

The other two codes are lean codes for Bank 2 and I doubt that Bank is lean because of O2 heater failure. You could clear all codes and see if the lean codes return after you replace the sensor(s). If they do, you'll need to look for a vacuum leak on Bank 2. Your best bet would be to have a smoke test performed by an expert BMW indie shop.
 

·
Under the lift arms
Joined
·
13,263 Posts
i WAS gonna go there... but im sick of it.. there is so much part throwing going on... I can hardly take it
 
1 - 7 of 7 Posts
Top