There's this throttle body mod where u cut the diffuser off. Anyone done it? Pros? Cons?

1999 gmc jimmy sle 4.3 vortec

 

I did this to my blazer last summer. First thing I noticed is that the throttle was a lot more responsive from idle to about 2500 rpm, after that it's not noticeable. I suspect that it did help with MPG slightly as I was getting a couple more miles out of a tank of gas.

Is this mod amazing? No. But hey, it's free, cheap, and easy. I've seen no Cons since doing mine and only slight Pros.