Will it pass MOT with no backbox?

tommycx

Seat Leon SX TDI 110
Dec 13, 2011
95
0
Somerset
Would my car pass the MOT if i cut my backbox off and then replace it with a straight bit of pipe in its place? :confused:
 

Seatmann

Rough around the edges
Sep 16, 2010
5,568
9
Scotlanda
I haven't heard of any not passing yet, I don't think they're loud enough to fail and the emissions test is easy.
 

Seatmann

Rough around the edges
Sep 16, 2010
5,568
9
Scotlanda
Would my car pass the MOT if i cut my backbox off and then replace it with a straight bit of pipe in its place? :confused:

I spoke to my MOT man today, he says you don't need any boxes at all as long as the car's not to noisy. That's all the boxes are for after all, noise, the cat doesn't matter because we don't have any strict emission test for the tdi's yet so it's all good.
 

Seatmann

Rough around the edges
Sep 16, 2010
5,568
9
Scotlanda
They can't say anything about the cat because we don't have a cat test for diesels, just a smoke test but if the exhaust is to loud it can fail or have an advisory. I spoke to my usual mot guy yesterday though and he assured me that a tdi can have a total straight pipe and pass no problem.
 

Pimped up vario

Cordy Cruizer
Nov 20, 2009
1,291
0
Belfast N Ireland
a. A part of the system missing or excessively deteriorated.

Doesn't say diesels are excluded from this stipulation. As for the noise aspect it's not very clear is it? They don't exactly state a db limit. I forget what the police say is acceptable. Just as well diesel engines, although they are given the image of noisey, actually put a lot less energy into making sound than petrol engines so therefore are alot quieter.
 

Seatmann

Rough around the edges
Sep 16, 2010
5,568
9
Scotlanda
it's because of the turbo, it breaks up the noise quite a bit. I used to have a old renault 5 gordini turbo and all it had was a pretend box right at the back, little tiny straight through thing lol. Even that still went through the mot ok.
 

Pimped up vario

Cordy Cruizer
Nov 20, 2009
1,291
0
Belfast N Ireland
Mine has a straight through with one silencer and it passed the MOT. When I get my camera sorted (shower near caught fire this wkend, how many times do you have your head stuck in the electric cupboard) and post some pics of it you'll wonder how it passed. I was actually hoping it would fail so that I could force the garage to amend it. :D
 
Apr 13, 2011
1,971
1
hull
No diesels don't need a cat at the mo for m o t and would still passes as long as they pass the emmisons test but diesels are more just a smoke test unlike its petrol counter part

One thing I will say is te way things are going with emmisons these days and diesels being hit the hardest I don't belive it would be too long till diesel cars will hve to have a full emmision test
 
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