Question #1
Does anyone know the stock exhaust pipe size is for a 01 5.4L? My truck sounds like it has an after market exhaust but from what I can tell it doesn’t. It has the stock cats and what looks to be the stock muffler. However it is 3" piping from the manifolds to the tip. My understanding was that they came stock with 2.5" piping.

Question #2
If 2.5" is the stock pipe size, is 3" to big? My back pressure seems to be a little weak. If you place your hand about 4 inches from the tip while the truck is running you hardly notice the exhaust hitting your hand. I am wondering if this could be the cause for the truck feeling a little sluggish.

 

2.5"-possibly weak due to running stock muffler

 

2.5" is stock. If yours is 3" thats not factory. Is it rusty looking? then its stock Is your muffler 26"s long, offset inlet & outlets?

 

Its rusty and its 26"s long but its center in center out.

 

26" long sounds stock, but those mufflers are offset inlet & outlet ro the right, hmm

 

yeah...that and the 3" tubing

 

The stock cats will give you more then enough backpressure then you would ever need.

Phil