[JYFarmer]

will a turbo back pipe straight pipe for a 2005 work on the new lmm or do i need to buy a new exuast syatem

 

[New 0mega]

It should work, but you'll need a Tuner to fool the ECM about the DPF

 

[BriteWhiteRam]

if your not worried about doing a little cutting and modifying if needed, and your not worried about your warranty then yes, it should work.
As well as New 0mega stated, you will need a tuner such as Quadzilla, PPE, or EFI live in order to disable the DPF system, otherwise the truck will operate in limp mode because of a "dpf malfunction"