jst de-cated my 93 wrx impreza and the decat pipe doesnt have anywhere for the 02 sensor to go , before i fitted the pipe i disconected the o2 sensor to see what happens , no engine warning light and it run fine , have herd there is a resister your supposed to put in place of the 02 sensor on the plug witch gives a varing current as an 02 sensor would any ideas?

 

on the 93wrx the sensor in the downpipe is not an O2 sensor.. but an EGT probe to check the cat temp.. gets called the cat on fire sensor..

your O2 sensor is in the headers.. look in headers below air filter area etc..

you can disconnect the cat not working sensor and just not refit it.. it is nothnig to do with ecu.. but a separate setup etc..

Simon

 

As above,did this on mine(changed headers too),not needed.

 

wicked guys , thanks alot for ya help puts my mind at rest now haha cheers!