4.7 with p0300 random misfire code

[SD4019]

Got the cel today. Has 216k on motor. Plus fairly new with around 5k on them. Won’t rev above 4000 rpm. Randomly the truck has a lag starting (like a few seconds of turn over then it starts). Seems like solutions are all over the place. Where should I start? Definitely don’t have money to throw at it chasing parts.

 

[Sherman Bird]

Start the truck and let it idle..... allow the idle to get settled down.... Take a piece of notebook paper and put it up against the tailpipe opening flat. If the exhaust tries to suck the paper back in a split second every revolution, you have a miss..... if NOT, the P0300 is a phantom code for another problem such as clogged catalytic converter, fuel pump/injector problem..... and so forth. You need to get it diagnosed!