I was using the factory 90/91 manifold with the O2 sensor at the top. Since it's hard to find one like that, I replaced it with a nice one piece 4-2-1 header with the sensor at the bottom (for 92+). After that, the car has poor idle and bottom end power (1500 to 3000). Above 3000 is fine. I tried resetting the ECU and driving for a few days but it hasn't helped. Is the ECU (OBD0 PR4) just confused because it's reading all 4 cylinders instead of just 1? And that the temp is probably lower 2 feet away? If I get a chipped ECU can it be tuned to better understand the data from the new sensor location? Or is this unrelated?

 

Bump

 

just get an exhaust shop to weld on an o2 bung up top. thats what i did. i didnt want to because i have a Spoon header but it had to be done. im not sure about the tune thing though. it could be reading wrong because its picking it up from a different place thoguh.

 

I adjusted my ignition timing and it helped with the idle, but still makes poor power cold down low. If only I could put a heated sensor in

 

convert it to 4wire bro. i had to on my old crx. its not that hard.

 

Don't I also have to convert to OBDI to use a 4 wire? Because the PR4 doesn't have the ability to control the heater