P0171 lean condition obd2 code on 1996 Mazda 626 engines

Symptoms:

This code P0171 keeps coming up even after resetting the code. Other symptom includes intermittent hesitation, surging when shifting in gears. Oxygen sensors (both upstream and downstream) show good reading.

Basic Concept:

This early OBD2 system is popular for mass sensor failure. It is attributed to the loose mass sensor mounting screws that get loose and would later allow unfiltered air to contaminate the wire elements of the mass sensor.

Repair Strategies:

When encountering this code, check first the mass sensor and its mounting screws. If loose, take the mass sensor out and clean the wire elements of the sensor with brake spray cleaner. When installing, use a locktite to secure the screws to prevent it from getting loose.

Note:

To get the exact wirings of the mass sensor wires including its color,please contact ATS.