john8704

I wouldn't recommend straight piping the whole thing(removing cats and muffler). Engines are designed to have some back pressure. With both removed you will lose low end torque while gaining some top hp. When removing the cats you also have to deal with the 02 sensor, pcm relationship.

the01kingranch

so just cutting off the muffler will be fine

Krack499

iTrader: (1)

Ya that's what I thought you were talking about the whole time

2thousand5.4

I'm not a big straight pipe guy but it does sound pretty goon on these trucks. I think magnaflows magnapack muffler sounds the best. It pretty much a strait pipe, the muffler just gives it a littler more tone and is deeper sounding. It's loud when you accelerate and you don't even no it's there when you are cruising. It's great check out a few videos on you tube

Here's my video. I got a 2000 5.4 and I just did a simple muffler swap

john8704

Yeah, it won't hurt anything. I prefer a nice sounding muffle with x pipe or h pipe

Krack499

iTrader: (1)

Not me I love mine loud I can hear it all the time even highway and love it

2thousand5.4

I wish mine a little louder on the highway and at idle, but I also have the stock y pipe and cats. I'm thinking about switching to hi flows but I'm worried about inspection

7700SCREW

I don't think he had any plans to remove any emission system parts...just the muffler .

Krack499

iTrader: (1)

Just move the pipes closet to the cab I'm running cat back 3" true duals exited before the passenger tire (lightning style) and I love it and i still have all my cats too

2thousand5.4

I ran a straight pipe with a dump in front of my rear axel for about 2 weeks. Sounded ok but I missed the tone of my magnapack so i put that back on. The straight pipes wernt much loaded than the magnaflow, if they were any louder it was at cruising speeds and that was just barely. But you have true duals so that might have something to do with it