P0300 Misfire cyclinder 4

I have a 2002 tb and i'm receiving a P0300 misfire on cylinder 4and there is definitely a mis. I have checked the connections as a tsb said. All injectors pass with 13 ohms.
I have checked the compression all cylinders pass with 215 - 230 psi.
I have replaced the intake manifold gasket. I have cleaned the injectors as another tsb suggested. Nothing helped. When the truck is in park and I step on the accelertor it will only rev to 3800 rpm. I suspect there is a rev limiter but I can't find anything that says' this. The other thing is when I put a monitor on it, the engine load is at 27% when idling. I can't seem to find any suggestions on why the load is so high while idling.
My next step is to replace the injector on 4 and see if that helps.

Any suggestions?

Thanks!

Hey man, i bought a 2002 bravada and had the same trouble. The thing with mine was that i could only go to about 3500 or a little more only in first gear. and the others would let it rev up a little more. Well i finally got a error code down the road and it was the oxygen sensor. the oxy sensor in the first bank in the exhaust manifold. After I replaced that my vehicle can now go up to 6250 rpm with no trouble. If you need to get that oxygen sensor off, the way we did it was we cut the wires going to it, used a deep well socket to get to it, started the vehicle up to get the cast iron exhaust manifold to expand and then we turned it off easy. If you try to do it when it is cold, GOOOOOD LUUUUUUCCCCCK. :evillol: :evillol: :evillol: Well i hope that helps you.