Ford Repair: ignition coil, damp weather, egr system

Question
2001 f 150 super cab   truck run ruff sometimes either on hwy or in town at idle.  We have had rainy and damp weather could i have a coil problem and how do I determine=mine which one.. The check engine light say I have a egr ?? bad  no other code.
I see there is a lot of question on the coils  Is 2001 a bad year?
I recently purchased this nice super crew but may return it.
I think the heater core may be going out as well only warm air blows out  Any ideas?

Answer
Although your truck did not have the first editions of coil packs, they are protected more in late models. It happened so much that it is the first thing one looks at, just as you did. That being said, if a coil pack was and is defective, there would be a misfire code. The symptoms that you mentioned of the performance, certainly can be explained by a defective EGR. I only wish that you had given me the code. If you do that, I can tell you which part to start looking at. Ford's EGR system is not 1 expensive component like GM and other manufacturer's.