FLASHING CHECK ENGINE LIGHT on 1998 Ford Expedition

WHILE driving,especially on the highway, my check engine light which is already on begins to flassh. trying to find more likely reason.

by in Oklahoma City, OK on August 13, 2010
3 answers
ANSWER by , August 13, 2010
This is a very serious failure of the emission control system on your vehicle. Have it diagnose ASAP by a qualified technician.
ANSWER by , August 13, 2010
You need to have a shop scan for codes to determine what repair is required and you can locate a shop near you here http://repairpal.com/directory?address=73127&car_brand_names=Ford and once they determine the repair you can check prices here http://repairpal.com/estimator?car_type_id=2317
ANSWER by , October 11, 2010
I own the same truck. Had same problem. The OWNER manual states, steady light usually an emmision problem. Flashing Check Engine light means a miss-firing cylinder. This can cause damage to catalytic converter, etc. Check plugs, wires, etc. My problem was a bad wire to cylinder # 4 (Most difficult plug to reach I have ever encountered) A miss-fire can and will also damage the coil. (didn't fix soon enough) Replaced wire and coil, and of course changed out all the plugs. Either reset check engine light with a scan, or drive 20-30 miles and if you did good, the light will no longer flash. Good luck. Denis