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I've got a CEL for oxygen sensor #1, is this pre-cat or post-cat and on the left or right while facing the car?

Also, are all four oxygen sensors the same, or is there a difference between the pre and post cat sensors?

My Bentley manual does not does not show this info.

TIA...:)

bump

i believe the oxygen sensor #1 is the one right by your engine coolant drain plug. It should be on the passenger side of your car by the headers. My CEL just went on today also, but i think its from me doing a coolant flush yesterday. Damn i hope the o2 sensor isnt messed up and CEL goes away after it dries up. Think it cost something like $150 to replace.

tks...I've got a Bosch replacement on the way, $143 (shipped) from Bimmerparts...

you plan on doing this yourself? let me kno how it goes

Gene V,

Could you tell me the model number of the Bosch pre-cat sensor? There are some ebay auctions for bosch o2 sensors (model 13231). anyone know what the model numbers are for pre and post cat sensor.

thanks in advance.

Originally posted by hamanncheese
Gene V,

Could you tell me the model number of the Bosch pre-cat sensor? There are some ebay auctions for bosch o2 sensors (model 13231). anyone know what the model numbers are for pre and post cat sensor.

thanks in advance.

Sorry, can't help you...got mine from bimmerparts and it's made by Seimens...