FEF84

I have high flow cats from SLP, how much horsepower will i gain with mods in sig?

socmguy

iTrader: (18)

very minimal

SSNISTR

iTrader: (10)

....a TON of RASPPPPPP.

ShevrolayZ28

iTrader: (4)

Cons: Illegal, raspy note, louder, potent fumes from tailpipe

Pros: A little bit of power gained. I think the gain would be single digit. It's not worth it IMO unless the car is running a power adder.

snake charmer

iTrader: (118)

You will gain a little though you are going to be raspy .

seawolf18

iTrader: (18)

I got rid of mine because I wanted it to be louder. However, we don't have emissions police here.

2002BlackSS

iTrader: (4)

About the cons people are listing...

All cars may vary, and all exhaust systems vary, but I have Pacsetters, custom ORY, stock catback with Magnaflow muffler swap, and I have NO rasp and only a slight gas smell that you can only smell when standing behind the car, which I consider to be more of an aroma than a smell on a muscle car. Moving cats from their stock location is illegal according to federal law, so if you have longtubes, you are breaking the law with or without them.

As far as power, I can't really say because I didn't try my setup with cats, but my overall gains were 30hp/30tq through an A4.