guysandiego

I searched but no results: I know someone must have done this... or knows the exhaust well enough

Was this a huge PITA? Is it a DIY?

No need to go into a debate about trq/hp - emmissions - etc.

I just want to know if its a doable job and what kind of hardache to expect.

I am not an expert but like to DIY -- I am the type who can change brakes and oil -- rig little projects -- not the type to assemble an engine.

maxwerks

why would you gut the cats ? why not just cut them off and replace them with pipes .. any decent muffler shop should be able to do that ..you can also replace the two downpipes all together with mandrel bent pipes ....for the secondaries , replace all with mandrel bent pipes to the center resonator

desired_speeds

gutted cats provide no HP gains because of the resonance, just sound and the bad smell.

guysandiego

thats a really interesting point -- I didnt consider the turbulence - resonance caused by gutting the primaries and leaving a large cavity in the piping.

I already have an X-pipe and H pipe -- no 2nds or resonator... just looking for a little more grunt.. A friend had SuperSprint from LT to the OEM mufflers - no cats or resonator.... Smell was no big deal for me -- sound was still rather tame til WOT.... So, my setup should yield similar results... I expect mine will be a tad quieter.

chawkins2001

Dont do it. I did it on my mid pipe to the secondarys and it is a b***h because the cats are made of hard metal mesh substrate. It took over and hour of grinding for one cat and you wont get it smooth.

I recommend straight piping that area and you will pick up HP/TQ by eliminating the bottle neck at the primary. You should pick up 10rwhp from eliminating the bottle neck by the flange, and straight piping the primary cats.

guysandiego

alright - straight pipes it will be

BBBSS

tell you to GTFO cause your $100 job isn't worth risking the $10,000 fine from the EPA for doing it.

Of course the shadier shops may not care, especially if you show up later near closing time perhaps.

benz_addict

I have gutted primaries only because the internals blew out. I leave them in because so it can pass inspection. And yes the interior drone noise is annoying as hell

guysandiego

Update - just kept it easy and had it straight piped. Sound is just as i figured.. a tad more sound - not raspy or drone -- just a little more muscle. I am happy.

Only regret: should have had all the cats and res deleted @ the same time--- would have saved some money.

ygha

Sound clip please ~

guysandiego

Very reasonable request - I will see if my wife we help me contribute to the site. I cant promise good results thou -- I have a really modded intake and pulley that allow you to hear my car scream like a banshee...

For the meantime-- I highly suggest u gut everything if you can and add an X-pipe... with the OEM mufflers you will not get drone or a loud car... it still seems quieter than a GT mustang.