Now after having driven my car for a few days with the new exhaust I can positively confirm a gain of 2+ miles per gallon. I wouldn't have believed it until I tried it, it makes little sense. I'm not complaining though...

MarcB had posted even larger gains when he went to the Mina exhaust with custom x-pipe and upgraded pulley.

My change was only to cut off the existing exhaust after the stock center muffler and run 2.25" pipes straight to the stock rear mufflers. I had removed the resonators months ago.

My total cost for this mod was only $150, and while I "think" there is a small improvement in sound and small ity bitty power gain, the 2+ mpg is solidly there.

I would imagine a set of Nameless cats would further things this direction.

 

Did the center muffler delete and just took the rear resonators out. The Cat clearly sounds like it has a V8 now.

https://www.facebook.com/photo.php?v=4836799283231

 

Is the exhaust still going over the axle? Do you have an x-pipe or are you running separate exhaust?

Sounds throaty and mean, like it takes no prisoners

 

How does any of this impact smog testing?

 

It should have no impact at all because it is aft of the cats. However, CARB might have a different take on it.

 

Interesting, I didn't notice a change in mileage with a full catback x-pipe exhaust.

 

Thats a pretty serious improvement on the mileage, more like a 10%+ improvement. Pretty cool...