Hey if you go with a cat-less one you have no backpressure and your car might hop once or twice like mine at lights or at prolonged idel. You pick up a little more HP with the cat-less xpipe because theres less backpressure at WOT "wide open throttle" usually racing. The exhaust tone will be dirrerent, with the xpipe with cats the exhaust tone will be deeper, than one without cats. Also without cats your car might not pass inspection if your state has it. Also with no cats you will need to buy a pair of MIL Eliminatiors to keep the check engine light off since all 4 o2s are reading the same, when it shouldnt or you can get a hand held tuner to solve this like i did (diablo Predator).

anyhow any more questions im sure some of the guys will either add to my reply or correct me if i am wrong.

Goodluck let us know what you go with.

I have a 2003 GT with the magnaflow exhaust not the packs and the magnaflow off road x-pipe. I love it. I got a chip at the same time so I did not need the MIL eliminators. I love the sound and so do the people around here. If you have to pass emissions then you better go with the cats.

There's a great article in the Dec. issue of MM&FF called "Sound Thinking", check it out it will really answer some of your questions.

Kyle82484 said:

Im in the market to buy an X-pipe for my 2003 Mustang GT, right now I have a Magnaflow Magnapack catback system and I am interested in the Mangaflow off-road x-pipe, but I was wondering whether or not to get the x-pipe with or without converters? The prices for the two seem to be relavtively the same so can anyone tell me the pros and cons of each, e.g. which will make the most power? will they sound different? If anyone has any information I'd appreciate it.

Click to expand...

I have a 01 gt with magnaflow magnapacks and magnaflow off road x pipe withour cats and i love it, now im thinking about bbk shorty headers. Get the diablo sport tuners tho

^^^ threads 2 years old but would love to hear a clip of a full magnaflow exhaust. do they make headers aswell or no?

Personally, I would go cat-less if you are not worried about emissions and go with the X-Pipe. I posted something on back pressure recently that may be helpful.

As far a sound goes, I'm a flowmaster nut. Nothing sounds better to me. All my 5.0's had and my current 4.6 has them (2-chambers). Sounds meaner and louder than magna's in my personal opinion. But hey, I've only been driving mustangs for 15 years - just an opinion.

Peace brotha.

Ive seen magnaflow headers advertised somewhere before, i dont think it was long tubes tho, just shorties. I love magnaflow with an x pipe cuz you get the deep tone outa the magnas and a mean, raspy note with the x pipe to go along with it, so ya kinda have both sounds together. Oh and the o/r pipe should be like 100 bucks cheaper than a catted pipe.