VZ Maloo Cat Converter Broken

[Ripcell]

Hi all,

I have a broken cat converter in my 06 VZ Maloo, it is the standard car however modified to bolt up to the back of the 4-1s i have on it.

Last night it started rattling, i have taken it apart today and found it is disintegrating itself.

My question is, are all VZ 6.0 cats the same, could i get one off of a VZ SS if i cant find one from a VZ HSV, I don't really want to have to change to different aftermarket ones, and possibly have to get it tuned again if it makes it misbehave.

If i was to go an aftermarket set of cats on it, how much difference would the factory ones be compared to a set of say 100cpsi ones.

Im just a little paranoid that ill have to get it retuned again as last time i just changed the catback exhaust on it and she dropped around 30rw untill it was tuned again.

Thanks guys

[planetdavo]

Cat is part of the engine pipe on original, so yours has been cut off that.
Due to the design of how the pipes meet the cat back straight on rather than on angles like most VZ's (not to mention smaller diameter pipe), you'll need either the same model, or I "think" the VZ Monaro used the same part number.
I can double check tomorrow, but someone might be able to confirm in the meantime.

[HRT 8]

Im just a little paranoid that ill have to get it retuned again as last time i just changed the catback exhaust on it and she dropped around 30rw untill it was tuned again.

Thanks guys

Who ever told you this is so full of shit it isnt funny.
There is no way replacing a catback (unless it was something super restrictive and useless) that you'd loose 30rwkw
I'd suspect they charged you for said "retune" too, didnt they?


Replacing the stock cats (typically 400cpi) with 200 cpi cats will increase your exhaust flow. You wont need it retuned!

[tyrhantc]

Just rip the rest of the substrate out and put it back in...you will have the best hiflow cat on the market. :)

[Wonky]

Who ever told you this is so full of shit it isnt funny.
There is no way replacing a catback (unless it was something super restrictive and useless) that you'd loose 30rwkw
I'd suspect they charged you for said "retune" too, didnt they?

+1 Sounds like your tuner sees you as a cash cow, unless like mine he doesn't charge for retunes.

I'd definitely investigate getting a set of Sureflo Ballistic Racing cats. I'd bet my left nut they're cheaper than the genuine article and will flow much better. There are cheaper "no name" cats around on eBay (not all stainless substrate though) but I'd pay the extra for peace of mind as I know lots of guys with the Ballistics on everything from bolt-on to 500+rwkw cars and have not heard of one failure. Mine have been on 30,000km and my son-in-law's have been on his 325rwkw car for close to 50,000km now.

[Ripcell]

Interesting, it had the stock catback and went how it did, I built a new catback for it myself and it was noticeably slower, I stuck it on the dyno and she pulled 241, had it retuned and it pulled 272, it felt like it went like it did before I changed it.

I don't know the history of it's tuning before I had it, but it was a little wired it had a set of 4-1s on it and everything back stock.

Is there really much difference between 100 or 200cpsi on the road? The car will proberbly be cammed mid year so I'm guessing the answer is going to be go for the 100cpsi.

[planetdavo]

I don't know the history of it's tuning before I had it, but it was a little wired it had a set of 4-1s on it and everything back stock.


The previously owner probably sold off the (easily removable) cat back after re-fitting his original. Removing 4-1 headers is a lot more work, so if not doing yourself it's not really financially viable, particularly if you've cut up the original engine pipes/cats.

[G4RS_GM]

Would love to see, just as a comparison.....changing from YOUR stock HSV cats, to hi-flow 100cpsi/200cpsi cats, difference in overall dyno output.
Yes, i know the holes are x4 bigger or so...has anybody done this?

Hey, if your standard HSV cat/cats need repalcing, what better time to upgrade to some ballistics or whatever other hi-flow cats there are. Be good to see the change on the dyno output.

[Ripcell]

yeah, well i got the broken bit to come out today, so its definatly time for new ones, ill order some this week, i guess my next question is, are cats cats or is it really worth spending the money and going for some deerer ones, i had MSD (i think) on my SS, i got off of a mate when his VY was hail damaged.

Ill be fitting them myself, so stay away from ebay specials? do they break easier than the brand name ones?