i was wondering where the first o2 sensor is on a gsr and also ls header and downpipe. i looked at a gsr header(obd2) and an ls header(obd2) and i couldnt find anywhere on the gsr header for the 02 to be but on the ls it was right before the cat. im trying to pick up a header and dpipe for my b20 swap into my eg. ill be running an obd1 ecu so i only need the first o2. but where are the o2s supposed to be on the gsr and ls?

 

it is on the downpipe before the cat

 

GSR and LS headers are different. LS is about 7-8in longer and flange is turned. The bung for the LS is at the end of the header before the cat and if I'm not mistaken both the GSR O2's are in the cat. One in front and the other towards the end. I could be wrong.

Thanks, J

 

In my GSR (1996) the O2 sensors are in the cat housing. One at the beginning and one at the end.

-Jeremy

 

so what header do you guys recommend for my b20. i dont want to spend much $$$ cuz im heading down the turbo road fairly soon.