2002 Chevy Tahoe P0300 and P0430 Codes

Getting P0300 and P0430 trouble codes on my '02 Tahoe. It has 85k miles on it. The engine loses power when accelerating rapidly and at speeds over 60mph. Is it possible for a bad catalytic converter to cause misfires? I changed the plugs and wires... no improvement. Was thinking about replacing the fuel filter next. I'm ruling out an injector or coil because I'm only getting the random misfire code, not specific to any cylinders. Also checked the MAF and it's clean (also NOT running a K&N filter).

It's quite likely on that truck for the conveter to plug which will lead to a sluggish perfromance and misfire codes! I think the dealer even has tsb's pertaining to that!

I thought the PCM didn't use any data from the secondary O2 sensor for engine management???

It doesn't it's for catalyst efficency calculations which is one of your codes! Your misfires likely caused the converter failure or the misfires are caused by restriction in the exhaust. Check the converter by removing the 02 sensors and checking the restriction with a pressure gauge before and after the converter to see if it's restrictted! Check with the dealer for tsbs pertaining to this!

I have seen bad fuel pressure regulators cause the misfire code and can lead to excess contaminants in the cats. It is an easy check, while the engine is running, pull the vacuum line off of the regulator and look closely for fuel leaking into the port, and or get close and smell it. If it is bad, it's pretty straight forward to replace.