I think I would be doing a compression check. Even if you just do cyl 4.

 

You should be able to pull the intake manifold and access all 4 MDS solenoids. Sounds like it is not reengaging the lifters for #4 cylinder, so they are not opening.

 

Ordered 4 of them from ebay for $110.
Fingers crossed it’ll fix the problem gents.

 

While you have the intake off, be sure and verify that the wiring to #4 solenoid is good......

 

Replaced all four MDS Solenoids. And intake manifold gaskets. Cleaned Fuel injectors with a cleaning kit. And swapped out Coil pack for Cylinder 4 with new one. Oil is new. Coolant is full.

Codes P0304 & P1414 no longer come up...

BUT

The engine still shakes and now light white smoke comes out of the exhaust. And another misfire code.
P0300.

 

White smoke indicates a head problem. Either blown head gasket or cracked head.
Let the truck cool, then take the radiator cap off and start the engine. If you see bubbling in the radiator you almost certainly need a new head gasket, and probably new head.

 

I’ll test that today!
Would coolant leak in the oil and change the color?

 

You would notice the oil isn't right. That would be the head gasket at minimum...

 

What spark plugs do you have in there?

 

Bosch Platinum