Check engine light. P0430 code catalyst system efficiency bank 2. Question?

[Rob00Taws6]

I have a 2000 trans am, the car has Dynatech full length hearers, Y-pipe and catalyst converters. Also backed by a Corsa exhaust. The car also has a Granatelli MAF and a hi flow air intake. My understanding is that this code is caused by a bad catalyst converter, a bad 02 sensor after the catalyst converter, a misfire in bank 2, a vacuum leak, or an oil leak on that the bank 2 side. Just changed my plugs and over all the car responded well, but the code still pops up. There is no vacuum leak, and the car has not been burning oil. So that leaves the catalyst converter itself and the 02 sensor after the converter. Because the catalyst converters are only a couple years old I think I’m going to change the 02 sensor first. Any suggestions? I think I’m on the right path, but I can always use some input.

[2001NBMZ28]

You could swap the rear 02s side to side, clear all codes, then see if you get P0420.

[Danger731]

Do you even have cats w your LT's or are you using o2 sims ?

[Rob00Taws6]

Both catalysts converters are on the car and I’m not running an 02 sim. Makes sense switching the 02 sensors before buying a new one for that side, think I’m going to give that a try first, thanks.