EvilEvo

Sorry Anders but no S4 was with out cat in sweden....
The s4 engine was develop for cat...

sweanders

There are a few non-cat S4's around and they were sold in the countries where fuel quality was low. There is a pair of mufflers instead of the cats if i remember right. Perhaps someone can dig up the part number?

Vilhuer

PET lists front muffler all the way up to '95. As far as I know few S4's (maybe half dozen) '87 and '88 sold new to Finland were all without cat. In some obscure markets like Arab countries it was used maybe even up to '95. For '87 part number was 928 111 096 01. It was replaced with 928 111 096 03. This should be direct replacement for converter but why would anyone want one when Ott X-Over is available?

Erkka

1992 928 GTS standard cat, for now
Oak Green Metallic 22L
Classic Gray MX

sweanders

Well, one reason is that they look more stock. It's pretty obvious that the OTT doesn't have any cats on it..

Vilhuer

What kind of idiots you have as inspectors if they can't tell difference between normal muffler and catalytic converter

Erkka

1992 928 GTS still waiting for it's first idiot inspection
Oak Green Metallic 22L
Classic Gray MX

sweanders

It's not the inpspectors I'm worried about (just have to swap the cats back in once a year) it's the eventual roadside checks by the police and a 1500 USD fine if I'm found to drive around without a cat. If it looks somewhat stock when just looking under the car without lifting it it's easier to pursuade them that it's stock.

I have ordered a OTT X-Pipe and waiting for it, should arrive any day now.

Garth S

Hey Anders,
If cosmetic disguise is the goal, why not find a S4 CAT that can have it's internals surgecially removed? It has previously been reported from unknown sources that ceramic plates readily yield to a steel bar.
If an Inspector figures that one out, he deserves his $1500!
Now, since you no longer need that Ott X - pipe, my address is .....

sweanders

Garth, good one.. hehe...

Well, I think the OTT pipe is a lot better since the exhaust pulses/pressure can win on scavanging between the pipes as where the stock unit is not as efficient.

Vilhuer

OK, it's just your police who's stupid.
Second vote for better camouflage. Find non working cat, cut those humps and have them welded on Ott pipe. Looks like cat and works like Ott.

Erkka

1992 928 GTS need cat one day every year
Oak Green Metallic 22L
Classic Gray MX

Vlocity

I was always curious if a gutted cat would create turbulence in the exhaust. The Ott X looks great is that run into a single 3 inch or is that
3 1/2 ?

Regards,

Ken

heinrich

Gutted cats work. My car came with them. However ... the Ott X-over ... that is a cat of a different colour ... can't live without it. Maybe slice open and weld a stock cat over the X?