2000 Ford Explorer got three codes need help!

KIRANORRIS

MEMBER
2000 FORD EXPLORER
6 CYL
4WD
AUTOMATIC
147,000 MILES

I have been getting code po303 for about 8months on and off.I comes on for about a day to a week then shuts off then a month or two later same thing. Then a week ago light came on and I got code po303 po171 po174. My truck runs allright it shakes in the morning when it is cold but once it runs for a min. The idle comes down and then it runs pretty good.I dont have alot of money and I need some help. If anyone needs more info let me know. Thanks for any help

1 Reply

JGAROFALO

MECHANIC
489 POSTS

The PO303 code indicates a misfire on #3 cylinder. This can be caused by the plug, wire, coil pack, or injector for that cylinder.

The PO171 and PO174 are indicating a lean condition on bank #1 and bank #2. This points to the mass air flow sensor. Check for air leaks between the sensor and the throttle body. Also check for air leaks or vacuum leaks around the engine.

The mass air flow sensor controls the mixture according to the airflow passing through it. Any external air or vacuum leaks will cause a lean mixture condition.