I now drive a 1998 Dodge 1500 and there is a slight ticking noise coming from underneath the truck when i am in the acclerator. You can also smell exhaust in the cab from time to time. Many of my friends told me that my exhaust is leaking and i plan on getting it fixed soon but 1) what kind of exhaust would you recomend and 2)will this help horsepower torque or gas mileage at all by doing this

 

1). Thats a pretty open ended question. a lot of guys running flowmaster.
2).Yes. As long as you can keep the right foot from being to heavy w/ the new exhaust, your gas mileage will be better. Not much tho. Might not even notice it. Its hard to keep your foot out of it when you havea nice new rumble from your truck.

 

I have a Magnaflow and love it, but sound is purely subjective. You'll have to hear it for yourself to be sure. Some of themanufacters' website have.wavfiles you can listen to if you want.

I saw a huge gain going from a stock muffler 2.5 in/out (like 38in long) to the magnaflow3" in/out(19" I think). Quicker pickup was most noticeable, gas mileage went up a bit, too. A higher flow muffler will let exhaust escape faster but most are louder than stock.Generally, the smallerthe muffler, the louder it is.

I think there's an Aero brand muffler thata few guys rave about, but they're pretty expensive ~$200.00 high polish Stainless Steel.
Flo Pro is a Flowmasterknockoff that a few around here like, Cheaper than the Flowmaster, but sounds close.

I upgraded the Cat and the muffler just last week and am very happy with the new sound.Butrtmorrisjr is right, it's hard to keep off the gas!