Drill the 2 spot welds that hold the cat in and take the whole plate out. If you have a torch you can hear up the deflector and stretch it out farther. Look at my profile picture. I noticed a gain by doing that over just cutting the gills out
Ehhh....i've run about 10 tanks through it now and i love it it definitely thinks its bigger than 40cc. I updated on the other threads i guess i forgot on this one lol.