Purchased the GENO's muffler elimination and have driven 1340 miles and the average MPG increased by 1.0 MPG average (calculated). Just had the highest MPG of 19.98 for a 311 mile trip with speeds through small towns of 35-45 and highway to 75. Did not notice any increase in sound. Very happy with this mod since the price of diesel is up to $3.90 - $4.00 in my area.

 

will the performance change that much by eliminating the cat and muffler? I have had old trucks in the past, (gassers) that I eliminated the cat and the thing ran like a top fuel dragster!...well, almost

 

I just did the same thing that savage.basher did. All I have is a 4" pipe from the turbo back. No muffler or cat. It is kind of loud, not annoying by any means. I just did it yesterday, and haven't noticed any loss or gain in performance, but my EGTs are lower.

 

I'm guessing those of you doing this modaren't in emission check states either. I am in the process of relocating to the great state of NC and I think they check emissions. Anyone out there know this?