Hey just thought I would let all know that after I ran a single straight pipe (2 1/2) after my cat and brought it out before my rear tire I have gained almost 1 mpg so far. I hope it will continue to climb a little more after the computer is done recalculating stuff. Oh yeah I used actual math not just depending on the overhead computer. It was pretty close though. It actually underestimated my average by .2.
Not much MPGs but it all adds up in these gas suckers!!

 

I didnt notice jack when I did the same thing to mine. I still have the factory cat and a cherry bomb muffler.

 

I could see that happening if you ran the stock type system. The thing is about it though, you will only see improvements if you can keep your foot out of the gas.

 

Hey maybe it is the fact that you have a cherry bomb muffler on still, I dont have one at all. Yeah I know that the cherry bomb are supposed to be free flowing but it still is not as free as straight!

 

No ****. In pa i need to pass inspection. Ps that will screw up yr back pressure.

 

he has a cat, so backpressure is no problem
i drove mine on a straight pipe for a few days i liked it, but it scared chics that i would give a ride home from school, so i put a muffler on it

 

Easy "Killer", you are the one that said you did the same thing as I did which you did not. Also backpressure is not a problem with factory cat in place and the fact that it is only 2 1/2 pipe. More than 3 might indeed cause some issues oh and have a nice day!

 

I didnt know u still had the cat.

 

No problem just giving you some flack!! Hell Im just glad I gained a litte mpg no matter what anything helps in these trucks!! Hope yours works itself out. Hey you know I did hear of other people just welding on a muffler body to make it appear you still had a muffler for inspection purposes but I realize it may not matter if they place a "sniffer" on your exhaust. Just a thought!

 

I'm pretty sure in pa they look for the cat and muffler.