i've got a slight problem with my 2002 wrx sti. twice on long journeys, my eml comes on. i've scanned it and it says that the catalytic converter system, bank 1- efficiency below threshold. probable faults- catalytic converter, wiring, ho2s 2. after reading of faults, i can clear them and light stays off, at least untill the next long run. I have removed the second catalytic converter and replaced with a decat pipe. could this be the problem.i also removed the centre resonator pipe and replaced with a miltek item, and have fitted an afterburner vortex backbox.when the light does come on, it makes no difference to the way the car performs so its not bad enough to send it into limp mode. would a remap eliminate this problem? i dont want to reinstall the cat if i can help it.

 

This is a common problem on bugeyes, regardless whether modded or not...