Drilling out the cat converter

[POD]

I've read a few mentions on here of 'drilling out' the catalytic convertor on the Puma engine pipe. Can anyone explain in more detail what this involves? I have no knowledge of what the internals of the catalytic convertor look like, so would like to be armed with more knowledge before removing it to do this. Any pics would be great, but in particular, what does one drill? does it require a large drill to bore material away to the i.d. of the exhaust pipe? or is it as series of holes required to cut something away? I'm planning on wrapping the front pipe with heat shield material and would like to be prepared to get rid of the restriction whilst it's off.

[CraigE]

Not sure about drilling out, I know with some others it is a case of fitting a straight through pipe through the centre, however just be aware that whatever you do technically may be illegal if you get an inspector that knows what they are looking for. While I dont think the cat is a requirement in Australia modifying any part of a vehicle like this from standard can have implications. I would ensure first that this is a legal mod as I know on most petrol engine cars it is not.

[n plus one]

From memory, it's a big no-no on post 2007 vehicles.

Having said that, if I was inclined to modify it I'd pull out the entire section (need to pull the cross member and front prop to do this?) and drill out the honeycomb centre with a long bit. Alternatively, I'd fit a a bolt on de-cat pipe from one of the UK mobs.

Personally, I intend on fitting a full hi-flow system that includes a hi-flow cat.

[Naks]

My indie mechanic removed the cat and drilled out the innards.

Truck runs better - a bit more ooomph at low revs, reduced EGTs and also reduced heat by the driver's footwell.

You cannot do this if your Puma has a DPF, only a 'passive' cat.

[pannawonica]

From memory, it's a big no-no on post 2007 vehicles.

Having said that, if I was inclined to modify it I'd pull out the entire section (need to pull the cross member and front prop to do this?) and drill out the honeycomb centre with a long bit. Alternatively, I'd fit a a bolt on de-cat pipe from one of the UK mobs.

Personally, I intend on fitting a full hi-flow system that includes a hi-flow cat.

That's what I am about to do, I got a two piece from Gary at alive tuning? Being stainless steel with a bracket to mount the factory heat shield, you can chop the original and fit without removing the cross member and prop. Or do as I,m going to do remove whole and to preserve. It looks so good it could be factory! :

[Drover]

I removed my cat and centre muffler over 3 years ago.

Used stainless TF de-cat and centre pipe.

Definently better low end response and much cooler drivers floor, although I did wrap the de-cat with ceramic wrap.

[POD]

Yeah I'm aware that there are aftermarket front pipes available that replace the catalytic convertor, I was more interested in information about drilling the converter as I have seen mentioned on here several times.

[isuzurover]

The inside/matrix of a catalytic converter looks like this:
http://mkrd.info/uploads/images/audi..._before_sm.jpg


It is a ceramic matrix with a "wash coat" of rare earth metals.

[Tank]

The inside/matrix of a catalytic converter looks like this:
http://mkrd.info/uploads/images/audi..._before_sm.jpg


It is a ceramic matrix with a "wash coat" of rare earth metals.

.... and worth anywhere from $120 to $350 scrap price, Regards Frank.

[frantic]

Not sure of the legality but to be safe when I replaced my td5 exhaust with a straight through, I put the old cat and mid muffler in the garage as if I ever get pinged will be much cheaper to refit