No load misfire in one cylinder. Codes and some tests already done.

I’m slowly running out of ideas here…. 2004 Jeep Liberty, with the 3.7l V6. Really bad cylinder no.4 misfire at idle, but with some load on the engine, it clears up.

It’s showing p0304 cylinder no.4 misfire

P0300 multiple cylinder misfire

P2311 Ignition coil 4 secondary circuit insufficient ionization

P2305 Ignition coil 2 secondary circuit insufficient ionization

Live data shows a very consistent misfire in cylinder 4, and rare, occasional misfires on other cylinders

So far I’ve already swapped coils and plugs around, and the misfire didn’t follow.

Opened up the PCM to see if anything was obviously burnt out and ended up damaging it, so that got replaced with a brand new one.

Checked for, and repaired some poor grounds to the engine

Cleaned the cylinder no.4 injector

Did a compression test, and cylinder 4 was around the same as a known good cylinder. (Did it late at night. I want to go back and test all the cylinders again, just to double check myself)

I still want to do a leak down test, and send a bore scope into cylinder 4, but am I missing anything obvious before I start assuming the worst?