I just bought an 06 F-150 STX 4X2 w/ 4.6 engine. I have read about all of the posts about the different exhausts available for my truck but I still have some lingering questions.

Does my truck have 4 cats ?

If I decide to install true duals with the Flowmaster Super 44's do I just remove the cats all together (assuming there are ones located aft of the muffler)?

Thanks for helping a F-150 NooB !

Tom

 

#1) yes
#2) no

 

I stopped by a muffler shop today and the guy there told me I don't want to put duals on with the 44's because it would not have any back pressure and would run and sound like crap.

He said to run the exhaust into a single muffler and out as duals if I want but he recommended I stay with the single in / single out.

I just got out from under my truck and I only see two cats. Each are after the flange and in front of the cross pipe after that there is just one HUGH long muffler.

 

if you want true duals, just have them replace the stock 2.5" pipes with 2.25" or 2" pipes, you will have plenty of backpressure, and true dual flowmasters will sound great. But a SIDO(single in/dual out) wont be as expensive, thats what i have with the super44. it sounds great. he is right though, single in single out usually gives the most power. i still have all 4 cast on too. and i believe your truck has 4 cats, you probably saw the big rear ones, but theres smaller ones in front of those.

 

this guy doesn't know jack -hit!-if you true dual go no larger than 2.25"-if you sigle in do it- go no larger than 2.5" out-phil

 

the muffler man was right. I wanted true duals. I have a 98 f150 with the 4.6L but if you got true duals and took off from a dead stop. you would just be making alot of noise. You loose performance with true duals. Go with a single in dual out super 44, with 4 inch tips or 3 1/2. it will sound awesome. I have a cherry bomb pro with si/do with 4inch tips and it sounds really good. its not over loud but when i get on it you can hear me a quater mile away .

 

X2
Any true duel system set up correctly should perform well

 

i went true duals- ss mandrell bent pipe-2.25" ,x pipe at original y-pipe location- 2-siso magnaflow mufflers- excellent tq towing numbers now- top end gained as well- theres a reason mustangs have had true duals,-btw- will you share you true dual setup BRAD'S 98 4X4-? thanks-phil