I just got the non-sequential mod done and have a midpipe. Nayone out there have a hi-flo cat with the non-sequential. Supposedley a hi-flo will get you more low end torque. My car seems to lack the low-end grunt it had before but I'm sure it rips in the middle and up top - don't know though new engine Any ideas?

 

I am non-seq and I originally had a Pettit resonated mid-pipe but I was getting some boost creep so I put on my RP Bonez hi-flow cat.

With the hi-flow cat, the car was a little quieter and a little less stinky at startup. Not sure about the performance difference because I had not cranked up the boost while I was having creep with the midpipe.

 

Check out the 2 dyno charts here:

http://www.efini.net/myrx7proto.htm

You can see that the mid-pipe puts out significantly more peak power and torque, but the hi flow cat puts out more in the low end.