To punch or not to punch

[07commander]

I have had a hi flow exhaust fitted to my 07 crd commander for some time, it's a dpf back and the original cat remains.

I have tried a few reputable exhaust joint around west of melbourne and all i get is sorry dont know what I'm getting my self into or yeah will give it a crack but we cant quote it because it dont know what its going to take.
What worries me more is "we will give it a crack"

So my question is can i just punch the cat? will it throw a code or go into limp mode, the 02 sensor is pre cat I'm thinking it's possible but i dont won't to be stuck in limp mode while every one is scared to change the cat.

[ren0vator]

I've heard rumours of people bashing a large screwdrivers into the honeycomb matrix of OEM cats Shame on them

Good aims of a high flow exhaust is constant diameter, smooth curves, gas speed and spin, etc. If the OEM cat is large, like a muffler, you will notice a difference, but if it's just a small cannon it's a waste of time.

Best pull a system off a wreck.
Make a small subframe, mounting jig, that models your car.
(a lot of stuffing around)
Then find an exhaust shop with a mandrel bender, who can supply high flow cats and let them go to town.
Either way first (unique) is always expensive.

Any in the States?

Hope that helps
Mark

[07commander]

It's the cost of this exercise that scares me, if i can get a cat for next to nothing i could make the jig but how much would i get charged?

Already paid $2100 for the exhaust, i did look at a company from the states that does a dump pipe and high flow cat but wasnt that cheap plus our dollar and postage made it about $700.

[ren0vator]

Originally Posted by 07commander

It's the cost of this exercise that scares me, if i can get a cat for next to nothing i could make the jig but how much would i get charged?

Already paid $2100 for the exhaust, i did look at a company from the states that does a dump pipe and high flow cat but wasnt that cheap plus our dollar and postage made it about $700.

If you can make a jig so the shop doesn't have to go removing/replacing in a confined environment, it speeds up production time.

Hi Flow Cat & dump pipe for AU$700 sounds a bit high, but depends what it's made from. Mild or Stainless steel?

I've got mine off at the moment and it's a mess with this right angle turbo exit into pre-cat/joiner/cat/pipe mess. 3" dump pipe will definitely increase gas flow and thereby lower your exhaust temps, improving engine longevity. If you're planning on keeping your rig for many years, I'd encourage you to have a crack.

Cheers

[07commander]

Originally Posted by ren0vator

If you can make a jig so the shop doesn't have to go removing/replacing in a confined environment, it speeds up production time.

Hi Flow Cat & dump pipe for AU$700 sounds a bit high, but depends what it's made from. Mild or Stainless steel?

I've got mine off at the moment and it's a mess with this right angle turbo exit into pre-cat/joiner/cat/pipe mess. 3" dump pipe will definitely increase gas flow and thereby lower your exhaust temps, improving engine longevity. If you're planning on keeping your rig for many years, I'd encourage you to have a crack.

Cheers

Yeah i know $700 is to much thats why i didn't go with it, i can get a high flow cat for about $180-$220, i done a twin 2 1/2 exhaust on my v8 ute a few years back 2 high flow cats (magna flow) all the pipes, flanges and gaskets for $500, 2 high flow mufflers for $200 new off eBay, and pacemaker extractors for $450 new. i cant justify spending to much.

Sorry i cant remember what it was made from.

Yes they are a mess, also i have a cat back exhaust which i already spent $2k on with no cat (long story), i didn't notice any difference from probably because i still have the factory dump pipe and cat, which is why i want to change it.

Yes i plan on keeping her, its been good 230k on her and no break downs or major repairs, the only thing was the CV at T/C end when my diff mount bush let so $300 and a day under the car not bad.

[Mr_TT-89]

why not get the cat cut out put brackets on the cat and then do the same thing with a straight pipe so its a simple 4 bolt switch over and if any issues with CEL's or being Melbourne the local popo a simple switch over fixes that? Also from what i know if its PRE cat then it shouldn't throw a code as its reading it all before it goes to the cat not after when the readings are "off"

[07commander]

Originally Posted by Mr_TT-89

why not get the cat cut out put brackets on the cat and then do the same thing with a straight pipe so its a simple 4 bolt switch over and if any issues with CEL's or being Melbourne the local popo a simple switch over fixes that? Also from what i know if its PRE cat then it shouldn't throw a code as its reading it all before it goes to the cat not after when the readings are "off"

not a bad idea mr tt, but for the trouble of doing that how much harder would it be to do the whole cat and dump pipe. the only reason i was thinking of punching the cat is cause i could just unbolt the dpf and knock the cat out (20 min job) but i didn't want to be left with a car in limp mode.

Your spot on about pre cat, i know any car with post cat or both will throw codes etc, anything pre cat works cause it just needs the reading out of the headers, but i have never played with a diesel then alone a high tech one.