So it's a 2006 LS 2.2L

I'm getting these 2 codes.

P0420

P0326

there are no noticeable drivability issues.

I am not sure if I should go ahead and replace the knock sensor and O2 sensors or if there's somethjng else it could be?

Background, I have recently replaced the MAF, the ICM, the ignition coil pack, the radiator, and the heater core in response to several issues(check my other posts lol)