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.

Asked by for the 1998 Ford Expedition
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
Hey I have a 98 expedition I have had three people look at it and paid for three diagnoses to still have the Same problem #4 cylinder missfire did all plugs and wires but not the coil on the my truck there is two one on the passenger and one on driver when I picked it up from the last guy there was no light as I got on the freeway the engine light came on and started flashing I finally just took it to Autozone and it says the same code #4 cylinder missfire can it be the coil I am almost thinking of takin it to ford but didn't want to spend 130$ for them to tell me #4 is missfire when I know that what's the best cheapest way to fix this issue? It also gave me a code about ho2s1 switching and low input someone help please thanks ,Nick
3 answers 1 comment
This is a very serious failure of the emission control system on your vehicle. Have it diagnose ASAP by a qualified technician.
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