2000 K-3500 7.4l, for over a year I have had a issue with very low power after startup, 1-5 minutes. Truck acts just like cats are plugged until it just instantly snaps out of it and starts running fine. This occurs on cold start and on hot start though it takes less time to clear on hot start. Cats are not plugged, fuel pressure is within spec and does not change when the truck comes to life. Intake was replaced due to a coolant leak, new coil, cap, rotor, wires. No codes or noticeable problems showing on data. I have attempted plugging the egr as well. Nothing has made any difference on this problem. Truck has 177,000 miles on it and I have had the issue for at least the last 15,000 and just let the truck run for several minutes before I attempt to go anywhere. Any ideas???