An illuminated Check Engine Light could indicate that one or more of the ignition coils has failed due to excessive spark plug gap. To fix this problem, the ignition coils that have failed, the spark plugs, and all coil boots should be replaced.
2002 Ford Expedition Problem Reports
Most Reported 2002 Ford Expedition Problem Reports
There is a technical service bulletin for the V8 engines regarding a possible problem with the spark plug being ejected from the cylinder head, damaging the threads in the spark plug hole. If the vehicle is under warranty, cylinder head replacement is recommended. If the vehicle is out of warranty, Ford authorized the use of a specific thread insert to repair the head.
The mass air flow sensor (MAF) may fail resulting in a rough engine idle, hesitation on acceleration, and/or engine stalling. The Check Engine Light may or may not illuminate. A failed mass air flow sensor will require replacement.
Intermittent rough idle may be caused by the EGR sensor sticking, causing the EGR valve to stay slightly open. Our technicians tell us the valve and sensor must be replaced together to correct this concern.
The PCV hose may crack, causing the vehicle to idle roughly, this may or may not illuminate the Check Engine Light.
My 20 02 Expedition has 190,000 miles. It has been a good vehicle other than 2 fuel pump replacements. Idle normally 600 rpm. Last couple of days Idle oscillated up to 1200 and down to 500. When put in gear it was surging to 2000, with associated lunging.
checked for Vac leaks none noted. Cleaned the IAC Seams to have resolved the problem