i have an 04fx4 with the 3valve triton. has anyone cut the y pipe connector and put in a di/so 2 1/2X2 in and one 3 " outlet and then the three to the muff inlet and a do 2 1/2. or are most people going to a cat back and leaving it alone.

 

I'm not familiar with the new trucks, but the y-pipe collector on the older trucks is very restrictive. There's a few posts with pics and you can see how choked-down they are.

 

I just did a 3" si/ 2.25" do Magnaflow and I'm very happy with the sound and power. No loss in low end, maybe even some gain.

 

that y pip connector has to be restrictive. two 2 1/2 pipes into one 2 1/2 pipe and then to the muff. maybe since it has four cats the flow of the exhaust is slowed down enought to warrant it. but i think when i get my magnaflow cat back in i am also going to order a y pipe adapter. 2X2 1/2 in and one 3" out. then hook to the 3" inlet on the cat back and be done. when i get it all done i will take some pics of it.

 

Hi. That's the ticket!

Exactly what I'm thinking! Those factory 'Y' pipes pix are gruesome!

Cheers!

 

What posts have pictures of a modified Y pipe. I am interested in getting this bottle neck removed from my truck and want to now what to tell the muffler shop.

 

You'll have to do a Search for more pix (they are in someone's gallery and show how restricted the factory 'Y' is internally).

Here a quick pix I found:

https://www.f150online.com/galleries...3029&anum=2504

The solution is to install this - read the description, and it explains a bit how it's used:

http://www.troyerperformance.com/cgi...atalogno=10778

Cheers