Exhaust system

[stevieyid]

Hi im not the best mechaniclly so i need some help. I get a rattling noise coming from the exhaust. Where the exhaust pipes come down at the front of the car they then go into two box's. Are these silences? It seems as though the rattle is coming from one of these boxes. Is there something inside there that could cause this rattle. At high revs it is not as bad. Thanks for your help

[Beetie]

They are Cats mate, and will effect the car, especially if it eventually gets blocked. What year is the car? If its an early one and you were thinking of upgrading the exhaust, i would just get some bypass pipes and throw them away. Also if you have a good mot tester ( ) and your car was a later model you could still do this anyway!

[alg]

Ceramic cat or silencer baffle deterioation.

[Fat Audi 80]

Ceramic cat or silencer baffle deterioation.

Correct!
I had exactly the same noise when I put my cats back on. BEWARE, the noise stopped after a while on my car and the performance suffered. It turned out the exhaust had been blocked by a piece of cat honeycomb wedging itself in the pipe behind the cat..

I would keep an eye on it... (ear )

see here: http://www.s2forum.com/forum/showthread.php?t=8602

Cheers,

Steve

[stevieyid]

my car is a 1993 k reg s2 would i still need cats? How much is a bypass pipe?

[The Spanish]

You need cats.
Is yours a 5 or 6 speed model?

[Fat Audi 80]

You WILL not pass the MOT without cats, my friendly tester tried everything to get mine though, I had to put them back on. I think the previous owner paid about £300 for the bypass pipes. If you have a home fry I can HIGHLY recommend taking the cats out, it really lets the turbo and engine rev properly at high rpms in high gears. You can "feel" the difference. Just a PITA putting the cats back on for the MOT....

Cheers,

Steve

[Beetie]

Thats why i said if you have a friendly mot tester! Mines a 93 3b. Is yours a 3b or an early aby? Mine flew through its mot with no cats

[stevieyid]

its a six speed. I could probably get it through a mot without the cats cos i no some people that would do it. Anyone know of anywhere to get a good by pass pipe

[Keeper of The Kitten]

Glad I have a '91! Didn't have the cats when I got it, bypass pipes were fitted.

Thinking about building a new dual system to the rear (currently a single 2.5" so two 2" pipes is a net increase), maybe even running under the rear subframe (ovalised pipes with same x-section for extra clearance) and straight out under the bumper instead of diverting to the cut out. I think I have more than enough ground clearance for this?

__MDC__

[porkkis]

Mines a 93 3b.

Huh. Officially there is no such thing. Does your VIN say N or M for model year?

[The Spanish]

its a six speed. I could probably get it through a mot without the cats cos i no some people that would do it. Anyone know of anywhere to get a good by pass pipe

In case you want to have cats, I have two 6-speed Cats at home if you are interested.

Cheers

[Beetie]

Huh. Officially there is no such thing. Does your VIN say N or M for model year?

Been through this many times before, it IS a 93 3b. Must be rare
And that is according to the vin plate.

[Beetie]

its a six speed. I could probably get it through a mot without the cats cos i no some people that would do it. Anyone know of anywhere to get a good by pass pipe

Milltek do them, but not sure on the diameter of the pipes.....

[S2central.net]

Been through this many times before, it IS a 93 3b. Must be rare
And that is according to the vin plate.

Neb - let me know the year code on the VIN. When you say '93 I assume you mean registered in 1993 so it could easily be a 3B that sat for a while... In the same way that a couple of late MY95 Coupes were held by dealers until they could get a 'P' plate. As for the 6 speed gearbox then it must have been retrofitted.

The other possibility is that it is a MY93 coupe with the 6-speed box and a 3B engine has been later fitted (not exactly a trivial job).


Paul