Mohammed_A Posted January 20, 2003 Share Posted January 20, 2003 Guys, I've read that a few of you lot have had a "full decat",removing the 1st CAT.Mine is a J-spec,I thought that the removal of the 1st CAT can affect fueling values and cause fault at the ecu. Plus...are changing front pipe's good?and are they worth doing..will they eliminate the 1stCAT???or is there another de-cat pipe which does this? Any help appreciated! Quote Link to comment Share on other sites More sharing options...
Alex Posted January 20, 2003 Share Posted January 20, 2003 Having searched the BBS for answers, if you can't visualise it you need to get it on a ramp and look underneath. There are 3 pipes in ANY supra exhaust. The Down pipe comes off the turbo's and contains 1 cat and one sensor (for the cat) The Front pipe holds one more cat. The rest of the exhaust might be in two sections but is generally reffered to as one Cat-Back (its cat-less) section running from the middle of the car back to the tip of the exit. Replace the first 2 pipes listed with De-cat pipes from Chris Wilson. Tie the sensor out of the way. 1.25bar Job Done. Make sure you only run high octane fuel, I would adivse the fitment of an FMIC if you don't have one and/or Water Injection. The fueling should be enough for this, just about. You will get less lag and lower EGT's. All good. If your Supra is a 1993-1995 j-spec it CAN pass an MOT cat-less. I've done it. By following the letter of the law they can't test it as a Cat fitted car. But keep the cats just incase this ever changes. Quote Link to comment Share on other sites More sharing options...
Mohammed_A Posted January 20, 2003 Author Share Posted January 20, 2003 Great info Alex! So this should no way affect my ecu and should make 1.2bar boost,it's a bit high isn't it(although high boost is good),but that won't blow the turbo's will it? I've already taken the CAT from the front pipe off..so its the one from the turbo downpipe next. how much does the 1cat replacement pipe cost roughly?(and which brand is recomended) Many Thanks! Quote Link to comment Share on other sites More sharing options...
Thorin Posted January 20, 2003 Share Posted January 20, 2003 Chris Wilson supplies the majority of cat replacement pipes to j-spec owners. The problem with removing both cats on the j-spec is that it can cause massive boost creep when you have a high flow cat back system too. CW's pipes are ~2.5" to still provide some restriction and should you end up overboosting after removing both cats he supplies a restrictor plate to fit to keep boost down. 1.2bar is deemed the safe maximum on stock turbo's. Quote Link to comment Share on other sites More sharing options...
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