Another Precat Question?

Andy_Coupe

Might be doing mine next week before getting the remap done, when i had the custom cat back system fitted it was blowing slightly where it joins onto the main cat, so they re did and sealed it with some sort of bonding crap, will this make it a pain the arse to remove and do i need to use some sealent on re fitting?

l7jnd

if they used proper exhaust paste it should actually make it easier to remove, just knock it round the edgses with a hammer to break the seal and wriggle it free. Would suggest you use some form of exhaust seal paste when you put it back together. Hellfords do it in a small tube, made by Holts.

Andy_Coupe

l7jnd said:
if they used proper exhaust paste it should actually make it easier to remove, just knock it round the edgses with a hammer to break the seal and wriggle it free. Would suggest you use some form of exhaust seal paste when you put it back together. Hellfords do it in a small tube, made by Holts.

Thanks, will pick some up before i start on it next week! One other question, how much louder will my exhaust be? I have a custom cat back which is a nice rumble and i dont want ruin it.

l7jnd

Removing the precat on my coupe made hardly any difference to the sound, maybe a little louder at some points but hardly noticeable.

blue_se2

Andy DO NOT put paste on any part of the exhaust before the cat after is fine but not before.

Andy

yeah putting exhaust paste before the cat is a big no no.

JohnnyN

I suppose i've got to ask the question. Why no paste before the cat? Is it because some paste could flake off and block the cat?

:oops: what.. :oops:

Daz

Yup ,does no good to the internals of a cat.One of the fitters in my works always used to use it until he voided the warranty on a new one and me boss had to stump up for it..

Andy

i'm sure i read it destroys the inside of the cat.

Andy_Coupe

blue se2 said:
Andy DO NOT put paste on any part of the exhaust before the cat after is fine but not before.

Thanks mate! This is the part with the 3 bolts that fits upto the manifold? should there be a gasket there? Doing mine on wednesday, appart from the how to on here is there any other advise/tips from experience?

l7jnd

yep there is a gasket between the downpipe and the manifold flange.

Andy_Coupe

l7jnd said:
yep there is a gasket between the downpipe and the manifold flange.

will this need to be replaced with a new one?