P1408 Ford - will a defective lower intake plenum cause this code

Question

I have a 1408 fault code on my expedition. I am finding chunks of plastic under the intake manifold. Could this be the lower intake (plenum)? Truck has definite miss and loss of power

Answer 1

P1408 EGR out of self test range

This code condition is for the EGR hose dealing with the EGR vacuum hoses. and the EGR passage, If the EGR was open the engine would have a rough idle and a lean code condition. and possible random misfire code. with a rough idle and low power the EGR under a self test will fail. if the intake plenum is falling apart you would hear a strong vacuum leak occuring. The loss of power may just be from ignition system such as a shorting ignition coil secondary ignition seeking ground. This is not a intake plenum problem.