I decided to take about 1 ft of the exhaust out before the muffler... i kind of like the sound of it. I can put it back on easily, it has some slip fittings on it. Is there any problem with running my truck 4.6 v8 like this occassionally?

 

you should be fine... i choped off my Y-pipe and just put turn downs right after the Rear o2's on my 97 4.6L i wanted True dual sounds without throwing codes so i just cut the Y-pipe as close to the o2's as i could and threw turndowns on there and it ran fine no probs No o2 codes and it sounded nice.... You should be fine with no muffler as long as your cats are still in with the o2's working. Ran it for a little over a year then i got some Longtubes