Did a lil search, found out these codes pertain to something the do with the EGR valve and more specifically something called a DPFE sensor. Anyone have more info on this? Looking for where its located at on the truck. Thanks

 

check the hoses for the dpfe. the egr ports can cause the 401 too. but the dpfe sensor fails often due to the heat and being plastic(some were aluminum) and thats usually the cause of the code. sometimes the dpfe will melt right where the hoses connect too. if you replace the dpfe, get motorcraft part only, and same with the hoses. do a suck test to the egr and if the truck dies or wants to die then the egr and ports are good.

 

Very odd to have those two codes at the same time. If you do have a 402, the EGR ports are not stopped up.
What Matt said about the rubber tubing from the EGR pipe to the DPFE may have holes in them.

The location of the EGR pipe is on the drivers side. A pipe comes up from the bottom of the exhaust manifold to the rear of the engine to a valve with a round disk(Diaphragm) on it. It also has to smaller tubes coming out of the side of the pipe. There is a rubber tube connected to each of these tubes, that leads to the DPFE.