sdh399

Hi everyone,
I have a 2002 bug eye wrx with an afterburner vortex back box. The afterburner kept me satisfied for a while but I'm now seriously considering partially de-catting the exhaust.

I think I'm right when I say the downpipe is the first step to take but I am worried about any bad effects changing it to a de-cat might have like engine problems or the CEL coming on. I have even heard rumours that the up-pipe cat can disintegrate due to the higher gas flow rates and destroy the turbo etc etc. I have searched for hours through the scoobynet forum but I can't find a definitive thread to answer my question.

I am sure I'm not the only one with this dilemma so could someone please share their wisdom? Is changing to a de-cat downpipe going to cause me any grief? Is changing the up-pipe/centre-pipe cat a better bet, or even a combination of two? Which sensors are going to cause the CEL?

Also, I live in Thailand and so I don't need to worry about any MOT test. However I have been told that my car is mechanically UK spec.

Any advice would be gratefully received!

Steve

RRH

take all the cats out, fit an 02 fix so that you don't get the CEL, or get it mapped out.

scoobiestu

yea best bet take both out and install new uppipe = most power!

pbee

if your car has a cat in the up-pipe for the £90 or so pounds it costs to replace the uppipe when you replace the down pipe it is worth changing it just for the pice of mind, in my opinion.

again you will need the cel fix for the 02 sensor or a remap.

sdh399

Thanx guys, am I right in saying there is an o2 sensor just before the uppipe, a temp sensor somewhere in the uppipe region and then another o2 sensor in the last cat? Which of these sensors is going to trigger the CEL? I think it might have to be an up pipe and downpipe and just leave the last cat. Any bad vibration sounds likely?
Also, I don't really want the exhaust to be THAT loud, the afterburner already sets off certain car alarms!