Someone educate me on 2006 4.0 error codes please

Short story long, moved to Hawaii in December. Used car market very rough, very limited selection / prices absurd / maintenance even worse.

Found 2006 Nismo with 208k 4x4 6 speed manual two streets over, last owners had it 6-7 years. Very very clean and well kept for Hawaii car at first glance. They had replaced radiator and done timing chain (no paperwork of course)
Bought it cause I was in a bind and needed a vehicle... starting to regret that now

Started losing power / misfiring / fuel pinging notably / issues with hot start here and there. Had CEL for Cats that I of course didn't check beforehand. Then the alternator shit out / left me on the side of road.

New alternator $1000 later... passenger side cat obviously bad, sounds like marble bouncing around. Had put a new good quality Bosch O2 sensor in upper bank as well on passenger side.

Pulled both upper Cats - right side was failing / already breaking down, punched out left and right, both gutted now. Didn't gut lowers.

Was having consistent cylinder 1 misfire - installed new Hitachi coil and spark plug. P031 code
Put in new crankshaft position sensor (OEM), changed both camshaft position sensors (Hitachi) P0335 code

Solved hot start issue / ran significantly better.

Of course I am still throwing P0420 and P0430 codes for Cats

Truck was okay / babying it around, but still getting the constant P031 cyl 1 misfire and now consistent P0300 random misfire code

Notably losing power again / misfiring / CEL has escalated to blinking; lugging the truck low RPM / high gear on a hill, like starting in 2nd almost immediately trips the engine and stumbles for power

Has evolved to having new codes like P0031 and then P1148.
Clear codes / pull battery cables / touch ground and hot together to hard reset ECM

Truck does fine for 40 miles ish then starts to act up.

I am making the assumption I need new fuel injector on cyl 1 to solve misfire after doing original coil and spark plug diagnosis. I believe electrical is okay - pull plug connector and it is obviously running on 5 cylinders / throws other code

Real question ... of course I have Cat codes 420 / 430, is this enough by itself to cause the cyl 1 misfire and escalate things? Or reasonable to think injector is next step? Maybe injector is failing, which is now contaminating other injectors for the random misfire code P0300 which is consistent, problem getting worse

Didn't know if O2 simulators / spacers / foolers would do the trick on the 420 and 430 codes. Do injectors and knock on wood good to go from there.

Not supposed to be working on vehicle at current house / no garage anyways, very not ideal for injector work. Also no free time and minimal tools of course.

Okay little truck, but sort of ready to walk away from it ... because its a 4.0L Nissan with 210k now...

Just hate to be pissing money at it constantly / of course mechanics 2 weeks out for seeing anything & I still need a vehicle to drive everyday.

Appreciate any feedback or suggestions about the Cats / troublesome cyl 1 misfire