After the truck sits for a period of time say 6-8 hours It will start up and Idle fine but once the RPMs reach 2500 or more it will backfire and then stalls. This will happen 2-3 times then it will start up and run like there was no problem at all. This started after I replace the crank/cam Position sensors. Maybe a coincidence maybe not. Only code that I’m getting is a P0300. I have replaced upstream and downstream O2 sensors, spark plugs, boots, ignition coils with no change. What Confuses me is that it will only do this two or three times And then runs perfect the rest of the day. Any advice would be much appreciated.