I have a 2000 Blazer (4wd 2d), and recently my cat clogged up to the point where it served as a rev limiter allowing me to go about 10mph tops. Unplugged an 02 Sensor and whoopdy doo, that cleared it up and in no time im going 60 again. However this is not a fix, as it is against the law. My goal is to take the cat converter portion of the exhaust off and replace it with a pipe while still leaving all 3 O2 sensors unharmed; however I dont know my years pipe sizes for input/output of the catyl. Converter. Anyone know for sure?