Code 44, Lean Exhaust Indication: Notes

Oxygen sensor acts like an open sensor circuit and produces no voltage when exhaust temperature is less than 600°F (316°C). An open sensor circuit or cold sensor causes "open loop" operation.

Test Number 1)  Checks to see if O2 sensor is registering a lean condition. Code 44 is set when O2 sensor voltage signal at control module is low (less than .3 volt) for a precalibrated period and system is operating in "closed loop".