I have a 98 Mustang GT with flowmasters on her. Lately ive been listening to a lot of sound clips with H pipes so im thinking about getting some. My question is do you have to have headers for the h pipe or can you have them on your stock manifolds?

 

you can have them on your stock manifolds. just make sure its not a short version of the h-pipe (which is normally used for long tube headers) and you'll be ok. are you going to go o/r (no cats)?

 

which is better o/r or with cats

 

well my personal preference is o/r, it's suppose to be "less restrictive" though it's only like a 1-2 hp difference supposedly. But do you have any kinda emission laws? Because if you have smog tests or anything like that you would want to have cats to pass those

 

I had a Mac catback installed the other day. I am also getting a H pipe. My question is How do you get by emissions if your using an o/r mid pipe? I know laws vary from state to state, but i live in Georgia.

 

Well I live in Kentucky and we have absolutely no testing at all. When you live in places like cali they do a test like once a year, and there in order to pass you either have to know the person who's doing the test for you and will pass you.. or I dunno about many other brands but with SLP they make what is called "race pipes" for their O/R x-pipes. These race pipes will slide out and let you buy the cats to slide in their place and then you can go get tested lol

 

do these pipes really make a difference as far as sound wise. or should i just stick with my flows

 

Yes they make a huge difference.