Worth every penny!
I love it! It makes my impala preform like I expect it to and more. I installed it the same day as a drop in K&N filter and my car sounds awesome. I deffinetly recommend this to anyone. It made my car fun to drive again. Not sure yet on any mpg +/- because I can't keep my foot off the pedal. I was worried about passing an emissions test but it passed no problem. Biy this, you won't regret it!