This is my truck when it had a flowmaster 40 on it. I've since opted to replace it with a 2.5 inch pipe which I recommend over the flowmaster.

http://www.youtube.com/watch?v=O8houm_eILU

 

Straight pipe? No muffler from the cat back?

 

http://www.youtube.com/watch?v=B5g0b...eature=related

 

Yeah, it's still got a cat, just no muffler. The stock cat does quite a job as a muffler anyway, no need overdo it. I like loud.

 

And the chack engine light doesn't come on beacuse of the lack of backpressure?

 

And the check engine light doesn't come on because of the lack of backpressure?

 

No, and the check engine light will never come on because of a lack of "back pressure". Back pressure is bad for your engine anyway.

The only reason your CEL light may come on if you gut your catalytic converter is because the post cat oxygen sensor, who's only job in the world is to detect if the converter is working or not, detects that it is not working, because it is no longer there. This can be eliminate with a spark plug non fouler or an oxygen sensor simulator.

 

Here's my truck. 5.9L with a Flowmaster 50 and a magnaflow cat. Sorry for the crappy/boring video, but you get the point.

 

OOOOOooo....now I like that!

 

back pressure is not bad for your engine nor is it great for it.. the reason some vehicles performe bad after all the exhaust mods is cause people use systems not made to go togeather pipe to big exhust expands and cools and velocity slows down giving the engine time to suck a lil back in at valve overlap... a good exhaust will have zero backpressure but still keep exhaust velocity up... that saying unless your willing to pay the price your prety much only going to get sound...