Can a faulty fuel door cause a 2006 Mercury Mountaineer to stall when driving?

What is your question?

The engine stalls when driving or stopping. Replaced the alternator and gear shift housing but the problem continues. Was wondering if the fuel door (capless) could be faulty and would this cause too much air to enter the fuel system? Or could it be the Idle Air bypass valve?

What makes this problem better or worse?

It's worse when the engine is warm

How long has your 2006 Mercury Mountaineer had this problem?

a month