Alright, so I'm looking to get 4 inch dual turbo back exhaust (MBRP), and was told that removing everything including the cat will not cause sensor problems, and asked about egr blocker etc, and was told this isn't needed for the year (2004.5 LLY, stock) is this correct? there will be no problems with engine lights or anything else?

some lly's will throw cel and so wont, from what i know there is no set way to tell if yours will or wont without trying. when i took the kitty out, i installed fingerstick at same time. also installed blocker plate at same time it blocks your exhaust from being recirculated into the intake tract of the engine.

I used my predator to turn off egr codes when I put on my 4" turbo back. Already had the egr blocker at that point. No codes either way.

I ran an MBRP turbo back on my 04.5 LLY and never got a CEL. It just goes to show that not all trucks get them.

Thanks for the advice/comments