Code 44 - Lean Exhaust Indication
Code 44 indicates the ECM has seen O2 sensor voltage lower than specified, in closed loop, above a specified TPS value and for a time longer than specified.
NOTE:
The following step numbers refer to the numbers in the accompanying flow chart(s).
- A fixed dwell of under 10° indicates problem is still present. A fixed dwell under 10° at idle, with dwell varying at 3000 RPM, usually indicates an intake leak. Check this area prior to replacing O2 sensor.
- This test checks if ECM is able to respond to a rich condition caused by choking the engine. If it does, problem is a lean engine condition, NOT ELECTRICAL.
- This step puts a rich O2 signal (about 1 volt) into terminal "9" of the ECM. Dwell should increase (lean command).
- If dwell increases to over 50° with heavy choking, fault is an air leak, since the ECM was able to respond. If air is going to the exhaust ports, disconnect solenoid(s) for the air control valve. If air still goes to the ports, it is a faulty valve.