Does anybody diag anymore before throwing money into shit first off is the truck running fine just the codes maybe the sensors are working as they should telling you there’s another problem rich lean something as simple as an injector can cause the cats to not do there job due to over fueling too much unburned gas can cause that code start simple without tossing parts at it test voltages they have online guides to diagnose the problem correctly Google the codes they tell you possible causes and how to test them but if you wanna burn money start downstream o2s then cats and go from there or cheap way out remove rear o2s from exhaust pipe block off holes with old o2s or a plug n zip tie sensors up under car.