Decat - pass or not on mot day

[Toby Davis]

Hi all

Lets keep this simple

Getting my cupra tdi (146,000 miles) a new exhaust system on Thursday

Want to go full decat, read old posts from years ago it should pass

Can someone please tell me if my car would pass or not with a decat ?have laws changed recently ?

Performance company im using claiming they would do a check for a cat in order to pass

I have explained a diesel does not need a cat to be in place and only needs to past the smoke test.

Why the hell are so called performance experts claiming it would fail when everyone else claims it wont and have had cars pass an mot many times.

Either they can or cant, which is it people ?

 

[CatB1]

It needs a cat to pass the mot, its not checked for emissions though. When I decated my tdi, I cut the cat out, gutted the internals & welded it back in position so it looked like it had a cat fitted.

Pete

 

[Toby Davis]

Thanks mate, I will get the garage to do that or put a fake box on then. Guessing rules have changed then as I read they didn't have to have one if it's on an older disesl.

 

[R3k1355]

The MOT now checks for the presence of the cat in the exhaust system, so if the tester see's it's been fitted with a decat they'll fail it automatically.

 

[Toby Davis]

So all the threads from people on here and other forums regarding diesel cars being except from needing a cat and that they should defo pass and have passed, no longer applies ? has the law changed then recently so any diesel car with a removed cat automatically fail ?

If that's the case then I will just keep the cat or have it stripped and put back on

 

[R3k1355]

Pretty sure it's changed, they check for the DPF now (on other diesels)

 

[Badger]

I had a decat with a ghost cat fitted (fake tube placed over the decat pipe)

Passed two MOTs at two different garages.

It's an automatic fail if the car was originally fitted with a CAT but isn't present for MOT also with DPF, they must be present.

 

[ryancoyle1989]

I have a full straight through on my cupra tdi but you will need a dummy box to pass MOT.

 

[Toby Davis]

With no silencer Ryan ? how does it sound ? does it make that awesome whoosh sound when you rev slightly on tick over. Mine didn't which I was disappointed about.

I went decat with a dummy box straight through to the back with just one silencer before the oval tip. Sounds slightly louder on full load and you can here the exhaust slightly from the inside as it sounds slightly deeper and meaner

 

[ryancoyle1989]

Yeah no silencer. Full straight through with oval tip. Nice noise from it and it whistles as well. Thinking mapping it good make the whistle even louder but im so far