Hey anyone on here have a 04 to 08 5.4l with true duals or an x or h pipe? I am looking to improve my sound and retain the proper back pressures, any ideas on what size pipes are gettign to big? Ive noticed most systems are no larger than 3 inch, but one thing i cant stand about prefab systems are those polished tips they put on. Im looking at series 40 Flowmasters of Banks monster mufflers.. I know that ill probably end up finding a shop to do custom pipes but i would like any input on sizes and configurations people have done and been happy with? Or does anyone know of a system that is offered in an x or h config? Id rather not have a split duals and have leaned away from getting forward of the cats just yet, but think that stainless would be a good investment. Thoughts?

thanks.

 

You can't get rid of the cats in most areas because of emissions laws, and also because they have sensors that the Engine Control Computer must have in order to provide proper performance. Still, it can be done if you're willing to pay for a proper duals system. I would think your local muffler shop could advise you on how to proceed.

 

ya, im not going forward of the cats... Today I checked a few shops and got all different answers on what i should do. some say use small tubes like 2.5 inches through one muffler and split it out....another said y pipe it to a 1 in 2 out muffler....and the third said do true duals, straight pipe out of each cat through 2 flowmasters and then dump it out in 3 inch pipes. I think ill end up doing the later, but still anyone with experience on the subject feel free to chime in.

 

On my '02 I had a single in, dual out flowmaster rust off. I told them to start there and put in a y pipe. There wasn't much difference in sound or performance. It sounded a bit better without the muffler, as it was a little bit louder, but not much. The cats quiet it down quite a bit.

 

I have an 06 King Ranch with the 5.4 and i had the local muffler shop cut the crossover pipe at the intersection. Then they cut the original exhaust system out totally. This was done when it had only 25 miles on it. I had 3in stainless lines and a single pass Flowmaster installed on each side. I have almost 50k miles on it and never had a problem. The original O2 sensors were not touched, the catalytic convertors are located close to the heads and therefore are not touched. GOOD LUCK with the conversion. By the way, the single pass flowmasters will give you a throaty boulevard sound, both at idle and on the highway