MK5 Golf GTI

All Things Mk5 => Modifications & Technical Area => Performance Modifications => Topic started by: N44LED on April 30, 2014, 10:19:14 am

Title: De-cat down pipe
Post by: N44LED on April 30, 2014, 10:19:14 am

Hi guys just wondering of any could lend a little bit of advise.

I've already got a milltek cat back but want to de cat my car I've put this off due to hassle with moting. But have since being able to get my hands on a stock down pipe but has the pre cat and cat deleted out of it so visually it looks there but hopefully a little bit more gain in power/noise.

The main thing that was on my mind was if I fit it is it going to knacker/not do it any good. With out having another remap as it's already on a stage one.

So can I fit it with out any probs or will it cause me problems with out a mapp.

Thanks for for any advise

Aled


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Title: Re: De-cat down pipe
Post by: Wardy91-ed30 on April 30, 2014, 11:35:00 pm

Will be fine to fit mate. Will just throw the cel warning light up for emissions probs :happy2:

Title: Re: De-cat down pipe
Post by: GrayMK5GTI on May 01, 2014, 12:41:59 pm

Are you removing the actual cat or just the pre-cat here? It wasnt clear from your post. . .

Pre-cat wont throw a CEL or give you any MOT worries. If you remove the full 800CEL cat then as said above, you get the MOT issues and the CEL light.

Title: Re: De-cat down pipe
Post by: N44LED on May 10, 2014, 08:18:21 pm

I've got a down pipe with them both removed wanted to remove the pre cat only but found a down pipe cheap with them both removed


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Title: Re: De-cat down pipe
Post by: asht42 on May 28, 2014, 08:04:29 pm

If its the ebay ones the quality is actually pretty good, but they will need modifying to fit with an aftermarket exhaust.

Bought one myself with the intention of cutting it up to add a quick change sports cat section for mot day ;)

Title: Re: De-cat down pipe
Post by: Orc on May 28, 2014, 08:18:53 pm

Dude I have a downpipe with the precat removed already off my edition if you wana buy it as a spare and still have your original?? Only want cheap moneys for it. Pm me

Title: Re: De-cat down pipe
Post by: Nickellis1 on July 07, 2014, 06:13:11 pm

I think he means he has a 2nd STOCK downpipe with both cats removed.

Without mapping it in you won't really see much gain, and may run the risk of running slightly lean

Title: Re: De-cat down pipe
Post by: chudds on July 07, 2014, 07:41:18 pm

What software are you running?! On stage 2 plus iv seen a little smoke occasionally I think that's the oil seals in the turbo so some back pressure is a bit easier on them...

I have just gone 3' down pipe and decat I love it :) really frees up the turbo!

Title: Re: De-cat down pipe
Post by: N44LED on August 20, 2014, 09:25:00 pm

Hi ye just got a spare off eBay with the two cats removed on it so if it caused me problems I could change it back. But my main concern was it running lean and doing more harm than good. Was going to get a de-cat down pipe but if it was inspected it would like like everything is there that's all.

Wanted to free the turbo up that's all with out having to mapp it yet, as wanted to take it to stage 2 but not at the moment

Title: Re: De-cat down pipe
Post by: Joshryan on August 28, 2014, 08:46:55 pm

I'm running stage 1 at the moment since added forge custom intake and a 3" decat downpipe ready to go stage 2 but I'm going to wait until I get autotech hpfp internals and maybe a fmic, so I'm going to be running the mods without another map for a couple of months. Not having any problems with cel light on if that's any help mate.

Title: Re: De-cat down pipe
Post by: N44LED on November 27, 2014, 11:12:23 pm

Arr right cheers that's what I wanted to know for now as I plan to do the same as yourself . Thanks Aled 


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Title: Re: De-cat down pipe
Post by: TyGTI on December 08, 2014, 09:55:41 pm

Quote from: N44LED on April 30, 2014, 10:19:14 am

I've already got a milltek cat back but want to de cat my car I've put this off due to hassle with moting. But have since being able to get my hands on a stock down pipe but has the pre cat and cat deleted out of it so visually it looks there but hopefully a little bit more gain in power/noise.

Just to clarify, I may have misread this.

Even if it looks like the cat is there it will still fail the MOT on the emissions test

Title: Re: De-cat down pipe
Post by: N44LED on December 09, 2014, 12:42:00 am

No you havnt it's just if you get pulled and they look and Carnt see it they can do you that's the only part I wanted to sort. The mot side can be sorted


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