So my truck has been having an annoying power loss issue that has been because of a bad primary cat. I was trying to get the dealer to fix it under the federal 8yr/80,000mile warranty but since my car is an 08 made in 07 they wont do it. Primary cats are crazy money and the local Porsche Performance Indy shop by be suggested gutting them. Has anyone done this? Curious on the sound. I'm sure it might throw some codes,but i heard that could be fixed with some extension kits for the 02 sensors. Shop said they have done it on a few Cayennes and Audi Q7's.

 

I would suggest buying aftermarket from Fabspeed or Hanks. I have read that hollowed out cats do not flow well. You can always pick up a used pipe on eBay or here for a few hundred bucks. A tuner can modify the O2 sensor limits or you can try extenders.

 

I agree that you CAN do it, but cannot recommend it either. Get an aftermarket set of high flow cats or cat bypass pipes.

 

I'm reading there will be a power loss with removing the cats due to the back pressure. Think that's true?

 

[QUOTE=JSavinoJr;4337632]I'm reading there will be a power loss with removing the cats due to the back pressure. Think that's true?[/QUOTE

You MAY experience a very small loss of torque down low-off boost but you wont lose any power and you will gain spool. You could buy a rolled cone in mild or stainless and cut out the cat, use the rolled cone to make the transition from the flange to downpipe. Why not pick up some used Cats from ebay?

 

You can also simply cut out the cats and replace with a piece of pipe. This would require building a simple jig.

 

I do not have a Turbo,it's an S

 

Any gain from it or was it a bust?

 

For an CS I would recommend OEM or aftermarket replacement. Unless racing then go without.

 

Dude, I have tried to gut the cats and those jokers are bullet proof!!!! I have gutted cats from early 80's Datsun trucks to a mazda RX-7, 4runner but these were a bear. So I ended up purchasing some cat bypass pipes and 250 bones later it's makes a nice noise!!! Not a $2500 noise but a sound I could afford. If you have an alternate drive you could pull the cats off and take them down to the local muffler shop and they may be able to weld, bend something up for you. Or at least they would do that about 15 year ago ha ha ha ha.

 

If you are talking about the shop cutting the cats off I doubt they would do that. With the society we currently live in (Sue Happy). They don't want to chance getting busted for cutting cats off vehicles even if the vehicle isn't there.

 

Ghostman, I just remembered a few months back mu buddy (city investigator) took his CJ to a local muffler shot ans asked if they could repair his exhaust and remove the cat, the muffler guy replied NOPE but you can bring it in and I will bend you up a replacement pipe. Maybe a Alabama thing but you sure won't get arrested or sued for asking.

 

Yeah most of the muffler shops in my area wont touch, they get scared. But I guess its all in who you know.