Re: 99 Windstar Fault Codes P0171 & P0174
Actually getting an error code P0171 and P0174 means that the air/fuel mixture is too lean. Most likely due to one or more of the following....
Dirty air filter, loose oil dipstick, dirty/defective MAF, dirty injectors, vacuum leak around the intake manifold, a loose vacuum hose, evaporated emmissions purge control valve could have a wire connector disconnected, or possibly bad O2's.
The Bank System refers to the following.
Bank one will line up with the number one cylinder and bank two will line up with the number 2 cylinder of your engine. From there you will have Sensor 1 which is the sensor prior to the Cat and Sensor 2 which is behind the cat.
Hope that helps.