JDB

iTrader: (2)

Then, why aren't your running stock cats? (Per your sig.)

From what I've read, the stock CTS-V cats are the exhaust restriction.

JDB

iTrader: (2)

I am wondering the same... since this worked on my '01.5 Audi A4 1.8 Turbo Quattro that I added a GT28R turbo and high flow cat... non fouler pulled the sensor out of the steam and rarely caused a CEL.

54inches

iTrader: (4)

My cats went bad.

54inches

iTrader: (4)

I was also referring to the aftermarket high flow design not stock. My bad.

With that said the newer style of OE cats flow just fine, the aftermarket just flow better, but I don't think either hinder flow.

It really depends on what your goal is.

I plan on headers with high flow cats in the near future and will keep the vehicle under 500 rwhp, so I think what I have is sufficient and would have ran the stock **** until I got headers.

My point is that everyone wants to take off their cats or their mufflers to open up the exhaust/remove restrictions, but generally this is not necessary. Replacement yes, but total removal no.

The aftermarket does provide a better solution and yes I guess removing them might open up a little flow, but cost does not equal the benefit.

I added mufflers and a REAL ex-pipe and did not notice a loss of performance at all, if anything I gained a smidge to the seat of my pants across the powerband.

JDB

iTrader: (2)

Gotcha... I wish there was another alternative than Kooks headers and cats to use with my Corsa and stay legal in PA. Its just not worth the cost + tune for power gain.

I8URSVT

iTrader: (2)

Im installing b&b headers and high flow cats soon, we'll see how it turns out.

54inches

iTrader: (4)

If you can weld or have a muffler shop close, then you can do pacesetter and other cats.....

Dmax/04V

Yes I do, had to pull the headers a couple times for miscelaneous reasons and it really makes life easier. The benefit of being able to just hang the gaskets, and headers on the studs when putting them back on is worth it alone.

54inches

iTrader: (4)

Arp 434-1301

Dmax/04V

Yes sir those are the ones I had in mind. Pricey like everything from arp, just make sure you have a 10mm ratchet wrench handy, as well as the appropriate hex attachement when installing the studs themselves. I believe I got mine here

http://www.summitracing.com/parts/arp-434-1301

sgtdestruction

iTrader: (1)

So I will probably contact Vengeance Racing in GA this week to see what options they suggest and how much extra $$$ I am looking at.

vmapper

iTrader: (8)

Bob's always a good guy to deal with:

http://shop.brutespeed.com/ARP-434-1...P-434-1301.htm