2.5L ('98-'01) P0304 code, CEL flashing; Engine running rough & loss of power

[rdaniel28]

First time posting on forum. Was driving on local freeway when I got continuous CEL indication and flashing intermittently. At the same time noticed rough running engine and noticeable loss of power/acceleration.
Upon getting home, read engine code as P0304. And I read not to drive with a flashing CEL as it could possibly ruin the catalytic converter.
So doing internet search, tested spark on #4 cylinder (on exhaust side plug) with inline spark tester. Tested fine. I then did compression check on all 4 cylinders (again on exhaust side plugs)
#1 - 160
#2 - 135
#3 - 150
#4 - 150
So at loss of why only cylinder #4 code comes up. From above readings I would think #2 cylinder would trigger (unless the problem is somewhere else
So I’m assuming to go the fuel injectors next. I have to remove the top half of the intake
manifold to get to the injectors. So that’s where I’m at right now.
Am I following the right steps here? I’m not a mechanic but I think I’m relatively smart and can follow instructions

 

[scotts90ranger]

It's either an injector or spark plugs, I had one once because the drivers side plugs and wires were factory at like 150k and the wire fell off one of the passenger side at the coil and burned up the connector on the coil...