Notices

Exhaust quick question..

Thread Tools
 
Search this Thread
 
Old 05 January 2007, 01:35 PM
  #1  
terence
Scooby Regular
Thread Starter
 
terence's Avatar
 
Join Date: Apr 2005
Location: Whitby
Posts: 450
Likes: 0
Received 0 Likes on 0 Posts
Question Exhaust quick question..

I know this is probably a umb question but im sure someone can answer it for me easily ...

I have a full afterburner vortex decat system to fit to my classic, say i decided to only fit the backbox and the centre pipe, leaving out the one that connects down at the turbo end, would this mean my car would still fail an emissions test?

Old 05 January 2007, 01:50 PM
  #2  
Heple
Scooby Regular
 
Heple's Avatar
 
Join Date: Mar 2005
Location: Lancashire : MY99 UK Turbo
Posts: 712
Likes: 0
Received 0 Likes on 0 Posts
Default

No it will most likely pass, The cat (downpipe) you are leaving on is the main cat.

Most cars pass with just the centre cat in place (With a De-Cat Downpipe) and that isn't as effective as the downpipe cat.

Craig

Last edited by Heple; 05 January 2007 at 02:05 PM.
Old 05 January 2007, 02:03 PM
  #3  
terence
Scooby Regular
Thread Starter
 
terence's Avatar
 
Join Date: Apr 2005
Location: Whitby
Posts: 450
Likes: 0
Received 0 Likes on 0 Posts
Default

sooo id be better off fitting the bbox leaving the centre cat and fitting the last pipe that connects to the turbo end? and would this way still pass an mot?

Old 05 January 2007, 02:04 PM
  #4  
Heple
Scooby Regular
 
Heple's Avatar
 
Join Date: Mar 2005
Location: Lancashire : MY99 UK Turbo
Posts: 712
Likes: 0
Received 0 Likes on 0 Posts
Default

No i think you have miss understood.

Fit the center pipe and backbox and you will be fine

Craig
Old 05 January 2007, 02:13 PM
  #5  
terence
Scooby Regular
Thread Starter
 
terence's Avatar
 
Join Date: Apr 2005
Location: Whitby
Posts: 450
Likes: 0
Received 0 Likes on 0 Posts
Default

ahh rite, i get you, so the decat centre section is the middle pipe, and the decat down pipe is the one that connects at the turbo end? the latter being the one that counts when it comes to passing an emissions test...

sorry, ive just never looked at a full exhaust system in my life untill I bought this one for the impreza
Old 05 January 2007, 03:28 PM
  #6  
Fat Boy
Scooby Regular
 
Fat Boy's Avatar
 
Join Date: Aug 2000
Posts: 4,262
Likes: 0
Received 1 Like on 1 Post
Post

For clarity it goes Turbo -> Downpipe -> Centre section -> Backbox. In classics like the P1 there is only a catalyst in the Downpipe as the centre section is only a resonator ( i.e. no cat just some baffling to change the sound) and the backbox is just that - a backbox. Other classics have an additional cat in the centre section but, as said above, if you leave the downpipe as it is you can do anything you like to the rest of the pipe and still pass the MOT.

Alternatively, you can buy a sports cat downpipe which is high flow, sounds like a decat and still passes the MOT - expensive though.

Finally, should you go for the full decat there are allegedly garages that will replace your centre section with a catted pipe for the test and then change back again afterwards. For about £70 a time, allegedly...
Old 05 January 2007, 04:09 PM
  #7  
terence
Scooby Regular
Thread Starter
 
terence's Avatar
 
Join Date: Apr 2005
Location: Whitby
Posts: 450
Likes: 0
Received 0 Likes on 0 Posts
Default

Brill! Thats exactly the explanation I needed, mucho appreciated!

Cheers guys
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
KAS35RSTI
Subaru
27
04 November 2021 07:12 PM
fatboy_coach
General Technical
15
18 June 2016 03:48 PM
FuZzBoM
Wheels, Tyres & Brakes
16
04 October 2015 09:49 PM
Ganz1983
Subaru
5
02 October 2015 09:22 AM
M4RKG
Wanted
4
25 September 2015 09:54 PM



Quick Reply: Exhaust quick question..



All times are GMT +1. The time now is 06:05 AM.