i took my muffler and rear part of the tail pipe off will this decrease my mpg and hp? also could this burn up my valve seals?

 

Wont decrease either might improve both a bit and i woulnt worry about the valve seals either cause trucks have been straight piped probly since trucks have been made lol about the only thing to worry about is a stiff ticket from the law over noise complaints

 

actually your low end torque might decrease a bit because there is very little back pressure

 

Nah, Valves will be fine.

 

The more free flowing the exhaust the better. Internal engine components will be fine. The more back pressure, the more work the engine has to do to overcome that pressure and push out the exhaust. That is no good. If it cant push it out, it cant pull it in and you are restricted.

Welcome to the board BTW.