Hi Im having trouble finding an after market cat for my 4.2 but there is plenty out there for the 4.4 and they look very similar. Does anyone know if they fit the 4.2.
I have LPG and the valve saver apparently kills the cats over time so was looking for a sport cat as the emission with the LPG are lower.

I thank you in advance regards Vinny

Java black 4.2 supercharged 2005 145k on the clock

Looks like you are getting about as many responses as I did... aside from
Importing from the us which will set you back about £500 a cat - dan can do for around £800.

These cars a crap for cats regardless of gas, mine without gas did one under warranty at 60k and the other at 110k. My 4.4 m62 version is at 185k on original cats on gas! Current stable:
2006 BMW M6
2007 4.2 V8 S/C FF
Gone:
2002 4.4 V8 FF

Lpg is much cleaner than petrol, does it actually need a cat?

Visually, it needs to be there, but are the emissions low enough to only need it to look like its there?

I used Jem Service in Hendon NW9 a couple of years ago after searching online for ages for an alternative to main dealers quoting £800 plus fitting for each side. They had an online presence which escapes me now, but their fitting service is at Jem Service.

They originally quoted about £500 to supply & fit but the cats for my 2007 S/C were different to the ones they had listed. They found the correct ones for my car in the US on eBay, so I bought them and they fitted them for an overall cost less than the £800 LR wanted to supply one side.

I have no connection with them, but found them very helpful and think it’s worth giving them a call.

Hope that helps.

Here’s the links to the two cats I bought from eBay:

https://rover.ebay.com/rover/0/0/0?mpre=ht...1887023648

https://rover.ebay.com/rover/0/0/0?mpre=ht...1516848606

Thanks for the replies, Ive been told that you can run theses without a cat as the emissions are good but by law they have to have or seen to have one, my thoughts are to take the old ones gut them and replace. It would be interesting to hear how the exhaust sounds after that .

Thanks again..

They usually don’t sound that great after that I don’t know if it’s because the gases hit the wrong places you’d be better with proper decat pipes and and try to wrap the cases round. Also what are you going to do about your engine management light that will be on as that will be a fail too - I looked into that option too Current stable:
2006 BMW M6
2007 4.2 V8 S/C FF
Gone:
2002 4.4 V8 FF

Just had a look at the ebay site and its interesting that it says the the cat is compatible with the 4.4 as-well as the 4.2 answers my question about the ready available sport cat systems of which are a lot cheaper.

Whatch this space as I may give it a go and report back.

Last edited by Vinnylondon on 28th Sep 2019 7:05am. Edited 1 time in total

Engine management can be dealt with a couple of 02 spacers at the rear so Ive been told and for £7 it might be worth a go.

A little research and basicly if you want to decat your RR you need to have the ecu remapped telling the system its running without a converter.

Get a sport cat and get it welded is a cheaper option - also be careful the early 4.4 cats have a smaller bore to that of the era of the 4.2/4.4 jag engine Current stable:
2006 BMW M6
2007 4.2 V8 S/C FF
Gone:
2002 4.4 V8 FF