Know there are numerous threads talking about this but most of them were from a long time ago. I have a 4.9 with the cats still but one cat is hollow and it's got a thrush muffler with stock piping. It sounds ok but I want more of a nice rumble. I also want something that might improve my mpgs a bit but still sound nice and loud but I want a single pipe. What would you all recommend? Truck is short bed if that matters. Thanks everyone!

 

The only nice sounding 4.9L I've heard is from a co-workers truck. Hers has no cat with dual flowmasters on it out the side and it sounds incredible when revving it up.

Unless you put a highflow cat on your truck you can't free it up much more then what you have.

 

Well honestly what size single pipe do you think would sound good and maybe free it up some more as it flows? And does taking cats off mess with the o2 sensors and cause bad mileage? My truck is a 91

 

o2 sensor is before the cats so no it shouldnt get messed up and you honestly should get better mileage

 

Ok I'm thinking about cutting the cats off running straight pipe to the muffler then dumpin the pipe right after the muffler. I wanna run bigger pipe though what size would be good for one pipe?

 

3"

 

Ok man thanks! I'll be doing this soon!