BimmerFest BMW Forum banner

1 - 3 of 3 Posts

·
Registered
Joined
·
57 Posts
Discussion Starter #1
Pulled a P0161 O2 Sensor Heater Circuit code.
How do I determine which of the 02 sensors is the problem.
I have swapped out the #3 relay in the control box.
Thanks in advance.
 

·
D'oh, You Kids!
1984 633CSi, 1985 635CSi, 1985 325e, 1987 325is, 1993 325is, 1995 318is, 1995 M3, 2003 F150
Joined
·
29,912 Posts
P0161 is heater malfunction, bank 2, sensor 2. That's the O2 sensor downstream from the catalytic converter on the rear three cylinders (4,5 and 6). Annoying as heck to get to. It may be a broken wire, but most likely it's the heater in the sensor that has gone south. I don't know exactly how to test one (I'm sure there's a way, but I've always just replaced the sensor) You'll need a 22mm open end wrench, or better yet, an O2 sensor cut-away socket. You may want to replace the Bank 1, sensor 2 at the same time.
 

·
Registered
Joined
·
57 Posts
Discussion Starter #3
Great info Ken. Have both tools and will get intimate with it. Car has 130,000 and I just replaced the injectors so its on to the sensors.
 
1 - 3 of 3 Posts
Top