i would like to get your experience opinions on this question. IF i remove the cat of my 97 accord and run straigh pipe from the header to the muffler where can i install the o2 sensor please try to answer.
Also i order the OBX header but i forgot to check whats the collector size. Do you know it? please let me know thank you.

 

A second o2 sensor on a car without a cat is pointless. You'll be better off running an o2 simulator.

 

I think the collector should be 2.25" and about the o2 sensor if you dont care about cels just cap it off and ziptie it somewhere.

 

You do realize that when the check engine light is on the computer is running in safe mode and will not perform at it's best.

 

Ofc

 

well the OBX header that i bought has two o2 sensor holes. One where the factory used to be and the and the other close to the cat. so do you think that putting the the o2 sensor on the extra hole that is on the header would work the same? and don't get the check engine light

 

The second o2 sensor is supposed to go after the cat. If you put the second one before the cat, the second o2 sensor will be telling the ECU that the cat isnt doing its job, and will throw a CEL. If you want to have the second o2 sensor plugged in, you must have a bung welded in after the cat, or if you dont want to have a cat, use an o2 simulator.

 

where can i get o2 simulator. or what is what it actually does.

 

i thought only california cars had 2 o2 sensors?

 

OBD-II cars (96 and up) should come from the factory with 2 sensors.