01 6.0 random misfire

[hardhead]

I have a 01 3500 with a 6.0, 168,000 miles. Recently while getting on the interstate it started bogging like it was loosing power and the service engine light was flashing. The light stopped flashing after a few seconds but then idled rough so I checked the code and the only one it had was EGR low flow. I don't recall the exact code but anyway I went ahead and replaced the EGR valve since it has a few miles and now it still does the same thing at times but I get a P-0300 randon misfire. I have changed plugs, wires, fuel filter, checked fuel pressure, and compression. Fuel pressure was 45psi so I swapped the regulator with my Dad's and that didnt help so I changed the pump. Same issue so checked compression and all were within 15lbs of each other, pulled the valve covesr and spun it over, looks like the cam is good and didn't see any broken springs. I drilled a hole in front and behind each cat to check for blockage and one side seems to blow a little harder in front than behind. I was gonna pull the fron 02 sensors but they were stubborn so I left them alone. I drove it with the holes open and it still did the same thing.