Cat converter replacement for 09 SIDI calais V.

[TOMCAT85]

Ok, ill start from the beginning.

Car started running bad a few weeks ago and the engine light came on, drove straight to a mechanic friends place to look over the car and he couldnt see any Visual issues, i borrowed a maxiscan OBDII to find the problem and found that it was misfiring.
He reccomended to change the plugs first as this would be the cheapest option, so $200 later and new plugs car runs fine for 30mins then light comes on again. This time it says low efficiency in catalytic something or other.( Sunday Arvo)
I decide that a more serious problem should be covered under extended warranty so i ring my local holden dealer the following morning and book the car in for the first available slot which is the friday. Over the next few days the car starts to run worse, starts blowing smoke, struggles to start a few times. Friday morning comes and i drop the car off at 8.15. They ring me at 9.30 to say that coils 1 and 3 and being changed and its all paid under warranty.
Picked the car up at 2pm, the girls says to keep an eye on it and ring if theres a problem. It ran fine, although something didnt seem right in the feel of the car. 3.30 comes along and engine light comes on again. i ring holden and get told to bring it in monday morning again.
Takes them most of monday to find out that apparently it needs some software update to reset some parameters or something, and also one of the sparkplugs i changed needs to be replaced already. probably due to the misfiring. $55 later and the cars fine again. That was last monday and then on friday just gone the light comes on again, plugged the scanner in and it says the same fault, P420 i think it was. anyway rang them and had it go in today only to be told that my extended warranty through allianz doesnt cover anything to do with the exhaust (Not impressed) and that its the right hand cat converter thats stuffed, possibly melted inside due to the misfiring and that a new one is $1200 fitted.
Ive rang around and got prices on second hand or after market ones, just wanting any info people might have on swapping one cat with after market or should i just bit the bullet and fork out the $1200. i also got told that the v6 and v8 cat is the same and that i could get a v8 one from an exhaust place 2nd hand, but barely used due to someone buying a new car and replacing with aftermarket straight away for $550 fully fitted.

Any help would be appreciated.

 

[Not_An_Abba_Fan]

Yes, the V8 and the V6 cats are the same, but I'm not 100% that the pipework is the same. Never really compared the two. I found this http://www.ebay.com.au/itm/HOLDEN-V...essories&fits=Plat_Gen:VE&hash=item461df1e7bc but it's LH.

 

[TOMCAT85]

From what ive been told, the SIDI exhaust is one piece from the manifold right down past the cat converter, i think thats a v6 one but not entirely sure.

 

[MURDERED-VE-INTERNATIONAL]

The LFX (& LF1 3.0L) V6 have the integrated exhaust manifold (= no headers)
TOMCAT85 is your motor the later LFX the same as this pic? (1 single pipe down each side of the motor)>

 

[MURDERED-VE-INTERNATIONAL]

You did not mention.......how many K's are on your Calais & what fuel do you typically run? When were the plugs last changed?
If one catalytic converter is stuffed good chance the other one will be also, $2400 all up if you want to buy 2 new genuine ones according to the quotes you got, Stuff that

Either way I would be buying a pair of 200 cell hi flow (Still legal but gives you a bit more flow) Magnaflow catalytic converters, At $141 each incl postage you could easily afford to take it to an exhaust shop & have them fitted

Even after fitting these will work out at a really good price>
Magnaflow High Flow CAT 2 1 4" 200 Cell Metallic 59955M | eBay

Being an exhaust fitter/welder myself (I would do them myself) I would take it to a well known exhaust shop that preferably does performance stuff & knows what they are doing, It should be a pretty easy job really to remove each pipe, Cut out each cat neatly, Reposition then tack weld new cats in position, Remove the pipes n cats again & put some nice welds on them, Fit them up & drive away
Any competent exhaust shop should be able to get them done with 1.5 hours labour each side / 3 hour total

 

[TOMCAT85]

Just clocked 87k kms and as i said the plugs were changed when the light first came on, so at prob 86k. i always run BP Ultimate and have since i got the car in January.
That pic looks like my motor, im fairly certain the VE only had 2 types of SIDI motors, mines the 3.6, those 200 cell hi flow wouldnt fit this would they?

 

[MURDERED-VE-INTERNATIONAL]

No reason why the Magnaflow (or similar aftermarket) catalytic converters wont fit apart from the body size or width compared to the stock cats
From what I can see any 4" round body cat will fit with no problems, There is 3" body cats available too, Not sure what size these are but something along the lines of these>

100 cell is not quite legal but still a catalytic converter & no one can really tell what they are internally once they are fitted
100 Cell Metal Polished Race Catalytic Converter 2 25" | eBay

Call some of your local exhaust shops (Someone on here should be able to recommend an exhaust shop near you?) & ask how much they would want to fit 2x catalytic converters on a VE V6 (FIT ONLY), The same or similar catalytic converters would easily be $200-$400 each at most exhaust shops

 

[TOMCAT85]

so they would just cut the old cat off and weld the new one in the same spot you think?

 

[MURDERED-VE-INTERNATIONAL]

Yep certainly, That easy!
Some of the European or Toyota etc genuine catalytic converters are up around $2000+ so fitting an aftermarket converter (Made to the same specs to suit) is about the only option, I have fitted plenty

They could possibly get away with welding each cat in position which will work fine but as mentioned to do a nice tidy job I would tack weld them in place then unbolt each header pipe at the motor & front of the exhaust system & do the welds on the bench for a nice clean job but I am a fussy prick, Sometimes it pays to spend another few minutes to do a good job the first time rather than trying to weld in spots where you literally cant see, Plenty of people will try to cut corners doing it this way

 

[TOMCAT85]

Ok, thanks for your help. ill go into some exhaust places tomorrow, you wouldnt happen to be in SA would you? lol