In my hunt for downpipe cats for my 4.2 XKR I found some fairly cheap X pipe center sections for our cars if anyone is interested. JAGUAR XK8 XKR 4.0 4.2 (X100) 1996-2005 SPORTS EXHAUST CENTRE SECTION X-PIPE | eBay

 

On second thought would these make it possible to fit the sleeve type downpipe catalytic converters to the 4.2 cars? It's just that no one seems to make catalytic converters for the 4.2 engines unless you go with the 200 cell cats that cost silly money.

Edit: I am pretty sure the normal 4.0 flange type downpipe cats will work for the 4.2 or am I wrong?

 

JAGUAR XKR 4.0 08/98-07/02 Catalytic Converter BM91002H + FK91002C I am looking at these cats at the moment,

 

The only difference I see on the 'flanged' outlet cataverters are the studs or holes.
Some have studs on the cataverters and some on the intermediate pipes.

Studs on BOTH would be a problem.

Holes on both could use BOLTS.

 

On the Jaguar drawings it looks like it's just a stud between the exhaust section and the cataverter (nice word). SNG Barratt UK | EXHAUST PIPE FRONT-PETROL Assembly I think the only problem would be the mount which apparently is different for the 4.2 compared o the 4.0. No idea why Jaguar changed this stuff for no apparent reason. Anyway it's not like Ihave much choice in the matter, I need new cvataverters and the only affordable ones are the ones I linked. If the mount doesn't work it might still be OK or I could try and rig up a mount to make it work perhaps. This is what the 4.2 cat looks like 98fa192f-e7b3-4ace-b184-8146782b6886.png (750×750) The BM ones are stainless steel as well so they shouldn't rust like the OEM Jaguar parts. I am surprised no one has had to replace their cats for the 4.2 engine yet on the forum.

 

If the studs on one the flange is a problem, could they be cut off and drilled out for bolts?

Jack

 

Looking at the aftermarket and the OEM cats the bolts should be OK but I wouldn't know until I actually buy them and try to fit them. I'm pretty sure the bracket won't work though but I'm not sure how necassery the bracket is?

 

I found one out of curiosity on Rockauto but one side only. They offer a "return and rebuild" service to my surprise for both 4.0 and 4.2's. TM

 

The inside of my cats are fine they still pass emmisions in the UK. The problem is that I have two holes on the bottom of the cat from rust from salty roads. The metal is too thin now to repair.

 

If you take the cats off and go to a welder they will be able to fix them for you. I welded mine up lying on my back under the car.