I have Pacesetter long tubes with two cats welded into the y pipe, o2 sensors before and after the cats. I want to remove the cats and was wondering if that will throw any codes.

 

Yes - OBD-II uses the after-cat sensor readings to determine if the cats are there and working. If they aren't, is will set codes/SES light for "low cat efficiency". You can have the codes "tuned out" of the PCM, or you can buy a pair os O2 simulators ("sims") that plug in to the harness in place of the real sensors. Sims used to be easy to find, but a few years ago Casper - the main supplier - was fined $70,000 and forced to stop making them, because their use is a violation of Federal law. You can find them on ebay, but like anything on ebay, the quality is going to be a crap shoot.