Hi Kremit and thanks for your response.
All parts that you listed have been replaced recently with the exception of the plug wires and I thought of that last night while browsing through some other posts. Local shop found only a set of Bosch wires (any good?) so I'll search a bit more for something nicer.
O2 sensors (both) replaced last year, MAF sensor was dirty once, Ford blamed the K&N drop-in filter (oil in filter coats the wire!!!) so I changed it out for an open element K&N without problem. Stock airbox was replaced when I tried selling the car, so maybe the air box is leaking some dirt into the MAF??!! I'll try getting that cleaned today.
Will check back later....
