De cat downpipe advice please

[edar]

Hello chaps.

Just some advice please. I'm thinking of replacing the down pipe and replacing it with a de-cat. I've already removed the other cats with a straight-through and wondered what the pro's and cons are with this idea. My 2003 WRX has already been re mapped and has a 4.5 inch rear silencer fitted. Currently, it passes the MOT emission requirements.

Any help would be much appreciated

[paulmoonraker]

You might get a bit more power, but you'll need another remap. Really though, you probably need to make other mods like changing the turbo to make it worthwhile.

You'll obviously fail your MOT.

[Ennoch]

What power/torque curve have you got with it still in place, and what other tweaks has it had (pump/plugs/intercooler Y etc)? You're unlikely to get over 300lb/ft or 290bhp with the stock TD04, even with the DP decatted. I did all of mine because it was all being done at the same time, but if it passed the MOT without any bother, and everything was already mapped for two of the three decats in place I'd leave well alone as it just wouldn't be worth the hassle, at least not for me.