Well the cat has been on for a couple of days and here is what i am finding out so far.
i havent lost any initial pick up off the line and if i have it is slight. still getting real nice scratch on held brake take offs. sometimes a lil chirp in 2nd, not all the time,,, the mid and top end is awesome. feels like it just has no resistance and i have nice pick up all through out the whole range.

we went out and did some of my favorite roads today w Txsman2930 and did 51 miles and 126 turns. just one fun time. to me Shaggy has more pick up in the turns now and it isnt a ton louder just a tad when you really stomp on it and it is really more of a lower pitch not really louder. pedal response from 20mph and up is really fun.

with the anti-sway bar, CGS and new exhaust, this lil HHR really gets w the program.

nest step is to remove the fog lights and put in air ducting to a Y and then to the front of the air filter.

muffler shop that did the custom cat said they could put in light weight aliminum tubing for me and i may see what they can do and how much, they are great and did a great job on the cat. bends and welds are awesome.

im going to start on that project tomorrow and see what i can do planning wise. i am looking at running the tubes through the bumper to keep it clean and out of the engine heat. will see if that will work