I tried somthing today,and to my surprize it worked great.Stock 04 FX4,removed the muffler,and installed a piece of straight pipe,took it for a drive,sounds great ,at 60 mph no drone.My buddy has the same truck,but with a 1000.00 exhaust system,he likes the way my truck sounds better than his,so we did a little race,I beat him,he could not beleive the results.It cost only 40.00 bucks for the mod,and the best thing is,I can reinstall my old muffler.

 

Sounds like a good deal to me!!! Only problem here is theres no way it would pass the State Inspection.......

 

seeing as he is from canada he doesn't have state inspections.

How loud is it with no muffler? I'm guessing the cats de a good job keeping it quiet?

 

Yeah I noticed....... which is why I mentioned it, I probably would have done the same if I could. Is it true theres actually 4 cats? Never took the time to look.

 

Knew a guy done the same thing and with the duals out back truck rumbled pretty good. Nice to be able to put stock back in . They cut mine right on the cross over and put in a 3 inch to the muffler. So no returning with out welding the pices back together . I did keep the factory exhaust though, its in the shed with my 03 exhaust LOL.

 

I did the same thing on my FX4 reg cab. Thought it sounded good. No drone in cab. Not obnoxiously loud. The only time it seemed kinda loud was when I started it in the garage in the morning when it was cold and the RPMs were up. So outta respect for my neighbors (I sometimes leave for work at 4am) I put a dynomax muffler on. It sounds pretty good.
I still don't understand people with different cat backs and mufflers saying that its too loud in the cab. With that straight pipe it wasn't loud in the cab on a regular cab short bed.

 

I rebuild that salvage F150 and have it running without a muffler on. It sounds awesome.

 

Any check engine light with running no muffler?

 

i done mine sorta the same way, except i cut the pipe before they came into one pipe and ran true duals, the left pipe is for the left side of the motor, same for the right side. it sound great, no cel, and seems to have more power.

 

I have read somewhere before that a properly operating catalytic converter has very little or no back pressure. It is pretty much strait through and the area that the gas goes through is very large inside (where all the honeycomb is). It just dampens the sound some because of the material that it goes through. An old, clogged cat is another story though, as it will KILL the power.

 

baja27 when you put in the strait pipe how exactly did you hook it up, I would like to try this as well but dont want to cut or weld, because I want the option of returning to stock....mayby you could take a picture.

Thanks

 

I took mine to the muffler shop on Friday and had the muffler cut out, and the straight pipe welded in. I too like it, it's not too loud, only on a cold start with the high idle. I noticed some popping/crackling if I leave the O/D off around town when decellerating which can be annoying so I leave the O/D on and let it coast instead.

I only saw two catalytic converters under mine when it was on the hoist?

I did notice that it is loudest at 1800-1900rpm and that is my normal cruising speed, but it's quiet enough that it doesn't bother me. It's definitely quieter than my straight piped duramax was.

 

Any noticeable performance gains/losses with the straight pipe?

 

I'm a believer in the placebo effect so I won't tell you it actually improved performance without being able to prove it to myself..

But it does seem to feel more responsive than before. I've only got 900 miles on the truck so I don't know if I "know" the truck well enough to be able to notice minor performance changes yet.