O2 sensor locations

[urmomsaniceguy]

Just to help some of you out. I finally figured out which O2 sensor is where as far as up stream down stream. both are heated but the on below the exhaust headers is the UPSTREAM. and after the CAT. is the DOWNSTREAM.

 

[CrazyM]

That's correct. The one closer upfront, is upstream. and further down the exhaust, down stream.

 

[quayzar590awd]

....Thats only been the case since obd2 was phased into production back in the mid `90's. Where have you been man?

 

[urmomsaniceguy]

yea i know this. but i have ran across many people that dont know which one is up and which is down. so i figured i would clarify to help people out..