To DECAT or NOT to DECAT?

[johnboii225]

The ths decat for the s3/tt is too long, because the tt/s3 exhaust just clamps together, wheras the LCR cat is smaller and has a flange on the end. Modifying it is a simple task as long as you know someone who can weld stainless steel. Basically you have to shorten the pipe then have a flange welded on. then its just a case of 8 bolts and its on

 

[Faisal]

then its just a case of 8 bolts and its on

EIGHT bolts???????uh oh....

 

[rickyjones1209]

nice one is it a new one? what is done to the second lambda? just spaced out?

is it loud without the cat? (motorway)

the second lambda still screws into the decat as does the first sensor at the front of the decat. the sensors are there to detect if the gases are right or not. with a decat the gases will be the same at both sensors which turns the EML on. if the cat is there then the gases are different when it gets to the second sensor, which is what its supposed to be like, so the light stays off. thats my understanding of it anyway.

i had the BF cat back first and that sounded nice on its own but its massively louder with the dp and decat on. sounds awesome though i am well happy with it and i'd recommend gettin one. it is louder on the motorway though especially at 80mph upwards.

 

[paul-murphys]

i have got a decat to fit, different people are telling me different things, do i need to shroud out the sensor or would it be ok to run wothout remiving the sensor, would a high flow downpipe be any good with a decat or is it the dacat that makes most the difference? i dont fancy paying hundreds an hundreds for a high flow downpipe, im going stage 2 soon an not sure which choice to go for, i dont ming changing my cat an decat once a yr for mot as its only a few bolts. please help

 

[rickyjones1209]

you'l find standard downpipe is split into two pipes whereas im guessing your decat is one through pipe. hence it wont fit without dp. Dp so ive read is restrictive and with dp and decat replaced it makes a massive difference. your decat will have holes to fit lambda sensors, you will have your EML come on but i didnt notice any negative effects of having light on. you will notice more of a difference and get the most out of your decat once you go stage 2 though.

 

[jwfcms]

i have the downpipe and decat, full blueflame system. no eml light yet have got the "wayne angle sensor mod" its a right angled piece that sits where the lamba sensor does then the sensor screws into that and it doesnt sit in direct flow of gases. i dont like the decat, it doesnt seem as good and too much noise. i am going to remove my decat pipe and weld in a sports cat 200 cell which will give it a bit more back pressure and run a bit better and quieter. cheaper option than the miltek sports cat and probably near as effective. decat pipe cost me £ 75 and then cat around 100 so makes a cheap sports cat which bolts up to my system and downpipe. easy job to do just cut the section out the decat and get the sports cat welded back in place.

 

[kineticz]

Turbo's aren't supposed to prefer back pressure? What doesn't seem as good - performance?

 

[Al]

Turbos like minimal back pressure mate.

 

[trevorb33]

one of the cheapest bangs for buck you can do, go for it