I was just curious if Straight piping and putting bigger piping on my 06 F150 is bad for the engine?

 

First of all, welcome to the forum!

If your just planning on straight-piping the muffler it will be fine, just make sure to unhook the battery for a little while so that the computer can calibrate for the change in back-pressure. Also, you shouldn't need any larger diameter piping its 2 1/2" from the factory and that should be plenty unless your putting out a ton of h.p with a turbo or supercharger or something like that.

Hope fully this helps you out.

 

I agree 2"1/2 inch pipe is plenty on a basically stock motor. Just have them cut out the muffler and slip on a piece of pipe unless you just need a whole new pipe. If you need a whole new pipe true duals might be a better way to go.

 

If you straightpipe from the cats back you'll be fine. I have a cherrybomb glasspack which I could look straight through, 0 restrictions, and have had no problems.
Personally I think the 2.5" tip is too small and think dual tips or a single 3" would look sweet