When I got my motor swapped in, my friend sold me an gutted itr cat to put on. Obviously the itr cat does not have an o2 input. If I have a obd2 gsr swap, what would the secondary o2 sensor be plugged into? I currently still have the stock motor and oem ecu.

 

a cel for the secondary o2 sensor would pop up because of the gutted cat unless you ran a cel eliminator or something along those lines. Some have zip tied the secondary o2 sensor to the shift stabalizer bar but thats a hit or miss thing.

 

you could either buy a real jdm itr cat and weld on an o2 bung for the second o2, or, do what i did and buy a universal magnaflow 2.5" cat and weld on the correct flanges. till then the second o2 isn't a performance killer...just annoying

 

i hate secondary O2s lol. i would zip tie it out of the way for right now and either have a bung welded in for the O2 or see if you can get that taken off your ECU without a CEL override. that way you keep your CEL for when you need to be informed of something in the future.