Cat welding

[v70tom]

Guys, is it possible to weld the catalyser on the v70?
It is not collapsed or making rattle noise, just blowing.
I replaced the rear exhaust couple month back as it was blowing and the misses was rebelling me having a straight through exhaust,
Acording to her it was to loud, now the cat starts blowing on the sides.
Sounds nice when speeding up but she is right is loud again.
Seems the oust side is aluminium or so, so aim not sure if it can be welded or maybe using
Fluid weld to fix this problem.
I don't want to spend money on a new exhaust or cat as they are not cheap.
Also I had the problem as it is a 2.5 outlet to find an exhaust to fit.
With a new cat which would come with 3 inch outlet I would need to get another bloody exhaust as well.

So seems welding is the cheapest option for another couple years or maybe fluid weld? Which is easier.

[nobananas]

Doubt the cat casing will be aluminium, never come across that myself. Have mig welded the odd cracked weld etc on cats but nothing where the metal being welded was in direct contact with the core. I think the core would be OK as it's ceramic and designed to take a lot of heat but don't know if it will like such heat in one localized area or if the bonding agent used to hold the core in place would be effected.

[Biff]

I've not welded a cat but I've brazed one with a gas torch & soft solder. It passed the emissions so it didn't harm. That was a §§§§ steel though.
If your cat is ally then it would be difficult but not impossible to weld the cast. You'd need a tig welder with a pulse frequency on it to stop it burning through.
I used to weld the cylinder heads for rework in Toyota & they were cast ally but obviously thicker material. You'd need a pretty experienced welder though & even then its no dead cert.

[v70tom]

So looks like I get some of this metall weld fluid stuff and try this one then ?

[Biff]

Possibly if its temperature resistant. I wouldn't see it as a long term fix on a forced induction car though.

[graemewelch]

attack it with grinder and mig it. am sure itll be find if it oe. or cut it out and replace with pipe

[v70tom]

If I cut it out and replace it? Is it more noise again?
So the "better" half has a moan every day?
Or would it influence the mot negative?
Been thinking about it.

Other then that, get this metal weld fluid stuff around and heatwrap the whole thing, plus get strong metal wire around over it to make the heatwrap improved to the pressure.
Got some of this stuff from the bikes, so wouldn't be any costs just this metal weld fluid stuff. Cheaper as a new cat!

[nobananas]

If you cut it out and put in a straight pipe it won't make much difference to the noise level but it will fail an MOT on both the emissions and also because the CAT isn't present.

[jotter22]

If you cut it out and put in a straight pipe it won't make much difference to the noise level but it will fail an MOT on both the emissions and also because the CAT isn't present.

If you remove the cat it will make a difference to the volume and the sound pitch!
i cant see a cat being made from cast ally everyone i have had a look at has been 1-2mm steel.

Tony.

[v70tom]

Ok thanks. Try going under the car this weekend. Lets see what's exactly happened to this cat and how bad it is.
If weather conditions let me.
Looked forecast and as it is weekend it say, " I §§§§ you're weekend up and will send you the rain clouds "