1998 Ford Explorer

1998 Ford Explorer 6 cyl Four Wheel Drive Automatic 152000 miles

My 98 Ford Explorer has a rough idle in the mornings when first started. We have replaced all 4 oxygen sensors, the pcv valve, new spark plugs and wires, new catalyctic converters, fuel injector system cleaned, new air filter, 2 years ago we replaced the idle air control valve and the mass air flow sensor, what could be causing this problem. Once it is warmed up, we have no problems with it idleing rough. WHat could be the cause of this problem
February 27, 2008.

Sounds to me like you need a new coolant temperature sensor, it is a common problem or hard cold starts or rough idle untill vehicle is warmed.

Feb 27, 2008.