De Cating

[s_i_hunter]

Bought of Ebay a spare Griff 500 'Y' exhaust section with the aim of removing the cat (3 cats - largest in the 'Y' section with 2 others in manifolds).

However, getting the cat out seems a problem unless I cut and rewled the downpipe?

Can anyone offer me advice on how to remove the cat and the benefits of removing the largest of the 3 cats.

[wixer]

I've just recently removed the pre cats on my Griff. One was loose in the pipe so I just managed to smash it along one side and pulled it out. The other one was intact, so I made a 'H' shaped cut on the bottom side of the manifold, gently rolled the two edges back to reveal the cat and then just squashed the cat down with a cold chisel and hammer until it was completely removed. Then welded manifold back togther. The whole process didn't take much longer than 20 mins. I would use the same process to remove the main cat, as the cats are a lot weaker at their sides than their ends, due to their honeycomb construction.

Hope this helps.

[BogBeast]

Been toying with the idea of a full decat meself since my precats 'fell' out.

Don't forget you will almost certainly require a different chip for the ecu (or a visit with Mark Adams)and a different tune resistor.

See www.pistonheads.com/gassing/topic.asp?t=80171 for more.

[simpo two]

BogBeast said:

Been toying with the idea of a full decat meself since my precats 'fell' out. Don't forget you will almost certainly require a different chip for the ecu (or a visit with Mark Adams)and a different tune resistor.

And a way to get your MOT!!

[BogBeast]

Indeed. I have a friendly MOT Tester, but I was condidering going temporarily replacing the y section with the cat for the MOT (and changing the tune resistor..)

[IPAddis]

I was also thinking of going down this route although a new stainless y-piece with no-cat from Tim Lamont at Act is only £235. Sounds like a bargain to me.

I've heard it's a bit tricky changing the y-pieces for the MOT though (I heard 7 hours!).

Ian A.

[wixer]

IPAddis said:

I was also thinking of going down this route although a new stainless y-piece with no-cat from Tim Lamont at Act is only £235. Sounds like a bargain to me. I've heard it's a bit tricky changing the y-pieces for the MOT though (I heard 7 hours!). Ian A.

7 hours would be to do the manifolds. I would thing even an inexperienced DIY'er could change the Y piece in little over an hour.

[IPAddis]

wixer said:

7 hours would be to do the manifolds. I would thing even an inexperienced DIY'er could change the Y piece in little over an hour.

I'm pretty sure he was talking about the y-piece. I think the chassis tubes get in the way of removing it.

Ian A.

[jellison]

Can you just get the Y piece though? - same for a 500 Chim I presume - Don't have to worry about rechip as LS6 not RV8 going in for alot more go and noise.

[starmist]

Removeal and refitting with new gaskets of the offside manifold took me 1.5 hours. Allow an extra 1.5 for the nearside ( as you have to remove the silencer) = 4.5 hours for manifolds, plus .5 for the Y piece (of piss) so 5 hours for the whole job.

TVR Power wanted 20, cos they don't like doing it!

[old64er]

Its not a bad job to take out the "Y" piece.
i had to drop the exhaust off and back to clear the chassis tubes with the y piece.
A cut and shut should be easy to do on the main cat in the y.