BADSEED

I have a 99 GT stock exaust, was wondering will i gain anything if i cut the cats out? how much louder does the car get if i take them out?

JJ03MustangGT

most people will say no, but i had an catted x pipe, and changed to an o/r H. before with the x i barely scrath third and it seemed to bog a little bit. when i went to the H i could just eat up second gear. it made a difference. and not to mention the sound. ditch the cats.

Zanador

Youll gain maybe 5 hp from cutting out the cats. If you can weld and do it all yourself, go for it (and no emissions of course). However, if you need to bring it to an exhaust shop, I would just get an O/R X or H, since they can be gotten for about 150 and you would end up spending atleast an hour of labor for the exhaust shop to do it, and it would flow better than the stock gutted like that.

BADSEED

whut i f i removed the cats and get an O/R X pipe how much would i gain then?

yourmom6990

i have an h-pipe.
can i bring it to a shop and have them cut the cats and weld it all up.

straitwangin

Oh just get a Saw Zaw and cut off the everthing passed the headers. But she will be really loud!


















Seariously dont do this buy an O/R midpipe for 150 bucks and bolt her up see if you like it or not.

silverstang1996

i dont think its worth the time/money to go catless, you have to put on your stock mid pipe everytime you get your car inspected unless you have a buddy that will pass it

MustangMan528

Dude, go catless. I have a full cat-back MAC catless exhaust o my car. It doesnt really add that much HP, maybe somewhere between 5-10, but you will definately be able to notice a huge difference in low end torque. The reason being is because there is less backpresure and the engine can breathe better without cats. Seriously, if anyone has ever seen the inside of a cat, it looks like a giant brick that all it's doing is restricting the flow of the exhaust. Trust me, go with a new catless mipipe.

03fireredstang

the shop that i got my midpipe put on does inspections, so im golden

Zanador

Mustangman, Backpressure is GOOD for low end torque. Backpressure keeps the exhaust moving at a nice velocity when the car is not producing enough exhaust on its own to move that quickly without the backpressure. This is exactly why shorties suck for low end torque, but do decently when you get into the high end rpm band, and why shorties are decent on built track cars, but longtubes are best for normal driving. Also, a high flow cat isnt much worse than going catless, and less hassle if you have emissions. If not, catless 100%.