Hey all,
I just got my dual dynomaxes and am about ready to put em on when I get the tips in, question before I install them, What about back-pressure? I'll running true dual 2.5" dynomax bullets. I've heard some rumors that I'll need an x-pipe to make sufficient back pressure? Any truth to that? or will i be fine running stock 4 cats with this setup on my truck? The motor is the 5.4.

Thanks for any help guys.

 

Back pressure is a myth there bud,
Yes running a X or H pipe is a good idea to help with Scavenging Read the Exhaust sticky it'll help make sense of the exhaust system.
https://www.f150online.com/forums/ex...ust-guide.html

But from personal experience I ran LT headers, no cats, X piped, Dual Borlas at 2.5" with no problems

 

ahhhh yes, I forgot about that thread, thanks for posting it!

 

No problem