When expecting a misfire the cat can be damaged very quickly.
Why are you wasting money driving the car through the parts store? Throwing 02s at it? Gotta watch the data stream and cause influence to it in order for a proper diag and repair.
Banks are sides of an engine. It doesn’t matter the cylinder count. Even a V4 or a V20. Each bank has at least a primary 02. Known as B1S1 or B2S1. Any inline engine will only have 1 bank, no matter the hole count.
I’m always open to suggestions, turboguy. I have taken car to mechanic twice, and P219A/P0300 did not reappear for them. I consider it a point in their favor that they did not throw parts at it and send me a huge bill. As far as me throwing parts at it...O2 sensors made more sense than going straight to cat replacement, battery was way overdue at 6 years/140k, spark plugs were also potentially overdue, air filter/oil/oil filter were due, i broke the coil assembly, and finally with multiple people suggesting PCV and a not unreasonable cost, I gave that one a shot. The car is my DD and I don’t have an extra vehicle to take to work unless I leave the wife stranded. In summary, I did my best with my limited time resource.
Misreading bank as cylinder was obviously dumb on my part but this forum straightened me out pretty quick.
Again thanks to everyone who has helped.