Retards and Decats

Smokey McPot · 27 Apr 2010 at 17:41

My willy is de-catted. No problems with smelly or sound. I've only done it because the existing catalytic converter is 17 years old and costs £300 to replace.

ShakenNstirred · 27 Apr 2010 at 18:01

when i fitted a decat to my rover 620sdi it was no louder and it spooled up on the turbo a lot faster at lower rpm and there was no more lag when changing gears.
well worth the £30

Matmulder · 27 Apr 2010 at 18:20

A decat pipe my GTA sound like a bag of ....crap:

Brap! Clicky

Gone back to standard now. However - it did make a big difference to throttle response, being crisper and more willing, so in that respect I liked it, just a shame about the noise.

Its a popular change on the Elise - my old S160 sounded fantastic, but I did have to refit it for MOT's.

Joshy · 27 Apr 2010 at 18:26

probedb said:
The car is also an old enough import that it doesn't actually need the cat for an MOT which is handy.

Pre 95 on imports :cool:

.

I'm rather tempted to decat the Soarer just because I can!

Agent_Smith357 · 27 Apr 2010 at 18:26

I love the smell of burnt petrol ! More people should run decats.

Xez · 27 Apr 2010 at 18:34

Simon said:
Complete myth, no 4 cylinder NA engine needs backpressure.

My S2000 has a sharper throttle and sounds better with a decat.

Have done the same with my clio, it just feels so much more free revving.

To the original poster

If the car is stinking because of a decat it must be massively over fuelling.

Alibaba99 · 27 Apr 2010 at 19:51

anticonscience said:
Correct, when I had my Impreza it was MOT'd by a garage where I knew someone there who was a technician, and he said emissions were not checked on as it would have failed (they knew about the decat). Yes it's wrong but hey.

This isn't possible with the current MOT. Unless the emissions are checked and the car passes the MOT certificate can't be printed. It is handy if there is another car present with a cat though

Jonnycoupe · 27 Apr 2010 at 20:49

Matt82 said:
in my EXPERIENCE, ive seen where the ecu will trim back the fuel mixture further and further try and compensate. the fuel trim ends up out of spec and hence limp mode and CEL lights.

why do you think people bother to make up emulators or disable the secondary lambda function if its only role was to trigger a light?!

So it doesnt go into 'limp mode' as you have just stated in the very same post as the question.