O 2 sensor bank 1 sensor 1 location on 2003 sierra

[ForrestMelissa]

Would like to know where the 0 2 sensor bank 1 sensor on a 2003 Sierra 1500 extended cab please and thank u

[txab]

Bank one is driver's side of engine. The "1" is for the #1 cylinder side. Bank "2" is passenger side for #2 cylinder location. You have 4 sensors 2 each side. 1 before the cats. 1 after the cats.

 

Bank 1, sensor 1 is Driver's side, before the cat. Bank 1, sensor 2 is driver's side, after cat. Got it?

Edited December 18, 2021 by txab

[tbarn]

Drop the "each side" and you are exactly correct. I know, nit picky, but it may confuse a novice.