This will prolly sound pretty newb but I was wondering what the deal with X pipe are. I have been introduced to them recently and am wondering what they do. My next question is can I install some type of x pipe (w/o cats) when i already had my magnaflow cat-back exhaust put on? cause the guy that put it on welded them together so would it be possible to have him put the x-pipe in? Last question is if i had the x-pipe put in, what exactly would it be replacing on my catback exhaust system? Thanks guys!
~Dave

 

Headers connect to the heads, then the midpipe connects the headers to the catback. So the exhaust system is really 3 separate pieces. You can put in the midpipe (X pipe) whenever you want.

Now you shouldnt be welding your exhaust at all. If he welded the catback to the midpipe then youll have to cut it where he welded it and put the stock clamps back on. All exhaust stuff is bolt in, not weld in. Except in some cases where you need to weld the midpipe together such as Dr. Gas x pipes.

If you get an o/r (off road) midpipe then that means it doesnt have cats. This is perfectly fine, however, its not legal. But many people run one anyways. You probably wont be able to pass inspection with it or emissions depending on how its done where you live. So when that time comes, youll have to put the stock one back on. Also, if you get an o/r pipe then youll have to get mils. These turn off the rear 02's that are used for emissions. Another way, and even better way, is to just get the rear 02's turned off via tune.

 

This will prolly sound pretty newb but I was wondering what the deal with X pipe are. I have been introduced to them recently and am wondering what they do.
midpipes are cross overs to equalize the back pressure created by the engine

My next question is can I install some type of x pipe (w/o cats) when i already had my magnaflow cat-back exhaust put on? cause the guy that put it on welded them together so would it be possible to have him put the x-pipe in?
yes you can have an x pipe installed....the welding of the catback will not affect the x pipe cause at the end of the catback there is a flange that attatches to the xpipe..and there is also a flange at the header.

Last question is if i had the x-pipe put in, what exactly would it be replacing on my catback exhaust system? Thanks guys!
you will not replace anything on ur catback...you are replacing your mid pipe...stock gt's come w/ 4 cats (or 6 if u have a 94-98 gt) contained on the x/h pipe..replacing w/ an aftermarket mid pipe you will usually reduce ur cats to 2 high flow cats or no cats..u will loose a little bit of low end power due to the less back pressure but you will feel the gain in the top end

you can also get an H pipe if u want...but the x pipe will yeild better results...

there are 3 parts to your exhaust....headers, midpipe (x or h pipe) and catback....

 

Thanks guys! Any suggestions if I should go o/r or catted? I want it to be loud, and have a nice sound, and maybe a little hp increase. I have heard o/r before and it is loud... but what happens if you dont pass emmisions?

 

Get an o/r midpipe. If you dont pass emissions then you cant drive the car. Well you could, but youll get a ticket. They might do OBDII where you live. That means they plug into your computer and if you dont have any codes then your fine. If thats the case then youll be fine with the o/r pipe and mils. If they do sniffer then you wont pass and youll have to put the stock pipe back on. Also, just because the midpipe has cats doesnt mean youll pass the sniffer. The cats are high flow cats and youll only have two compared to 4 or 6.