[flatlander937]

Bank 1 is your upstream o2, if you're getting codes from bank1, go ahead and replace it.

o2 sensors aren't cheap, but when they go bad.. well, as you can see, they are quite important.

Start spraying it with PBblaster and see if you can get it loose.

Some people are lucky, others.. not so much. I could never get mine off.

Our engines only have one bank. Our sensors are Bank 1 Sensor 1(before the cat) and Bank 1 Sensor 2(after cat).


OP your codes are referring to B1S1 which is directly behind the engine as viewed from above before the catalytic converter. Spray with PB for a few days then remove it while hot to get it out with the least fuss.

Edit: your pics are correct in O2 labeling.

 

[flatlander937]

what about pzevs, are they labeled as b1s3? I thought they were b2s1

@MediumLebowski; correct.

I believe so. B2 only applies on "V" type engines.... V6, V8, etc.

Edit: one exception is the Jeep 4.0l... first 3 cylinders are bank 1, last 3 are bank 2. (Its an inline 6)