Pre Cat?

[rushy]

Seen alot of talk about a "pre cat" and its removal. What is it, What does it do and is it worth removing it on a 2.2 petrol for more horses? :confused:

[rushy]

:bump:

[jamesv6]

hi mate a pre cat is just a cat befor the main cat. removing should free a couple of bhp if you have a perfomance exhaust.

[Gsi3.2]

IIRC, it's all in the same housing, just after the 4 into 1 exhaust junction, beside the bulkhead.. there is no cat under the car on the 2.2's... to remove the pre-cat will require you to cut open the can and re-weld it ..

i'd give it a miss personally.. ;)

[Ride-On!]

Will only give you a few extra horses. :car:

[rushy]

Welding mmm, think ill give that a miss. Thought it was just unbolting the pre cat pipe drilling holes around edge of the honeycomb then chissle it out, then replace pre cat and away toy go?

[Gsi3.2]

as i said, IIRC it's a one -piece sealed unit with the main cat.. you could knock it out but you'll have to give up getting it mot'd..

you could try a sports cat if you wanted, but the gains per pound are minimal..just get it mapped ;)

[rushy]

Penny dropped, got you. O well thought id stumbled across a free mod.

[dinac_cro]

it is a bit old topic , but maybe some1 need this again :)

http://www.astraownersclub.com/documents/technical/precat-z22.pdf

[beefycol]

rushy you been looking on the z22se web site? its only on the vectra bs has a pre cat off the manifold, then the cat under the car. our cat is off the manifold, so dont we dont have a pre cat

[Duncan]

The Z22SE has the cat off the manifold, as beefy said, nothing under the car.
The Z22YH has the cut under the car in the front exhaust pipe.

Neither have pre-cats.

The only engine with a pre cat is the 1.9 CDTi.

[rushy]

LOL beefy and D, this is a resurrected thread, look at the date of my last post.:)

[Duncan]

Ooops! :o I hadn't noticed the dates of the posts before dinac_cro had resurrected it! :o

[rushy]

Did you get round to looking at that pm duncan?

[beefycol]

opps haha, just look at todays posts and that was there, lol

[Nigel Harris]

...wow, can you get the 2.2 SRI mapped???????????

[rushy]

Sure can mate. Best to get any mods like Zorst, filter done first then get it mapped to get the full potential out of your mods.