2000 Lincoln Navigator V8 Four Wheel Drive Automatic 97000 miles
My Navigator runs fine, but the service engine soon light came on, went doen had the OBD read and it came up P0171 and P0174 OBD codes system too lean banl 1 and bank 2. Any suggestions? Replace all o2 sensors? Replace exhaust system, as I know it leaks moisture when left idling.
Ok lets start with the simple and inexpensive. Get a can of Mass Air Flow Cleaner, nothing else will work ok. Now remove the mass air flow unit. You simply undo the clamp that holds the air intake tube to the filter housing and remove the filter housing and clean spray the inside out making sure to spray the sensor that is inside. Now replace it and clear the codes and see if they come back. This will usually take care of this when the mass air flow unit is dirty. Let me know how it goes. If the codes come back then we will run a couple tests and go from there.