Code 44 - Lean Exhaust Indication
Code 44 indicates ECM has seen Oxygen (O2) sensor voltage lower than specified, in closed loop, greater than a specified TPS value and for a time longer than specified.
NOTE:
Test numbers refer to test numbers on diagnostic chart.
- 1) A fixed dwell of less than 10 degrees indicates problem is still present. A fixed dwell less than 10 degrees at idle, with dwell varying at 3000 RPM, usually indicates an intake leak. Check this area prior to replacing O2 sensor.
- 2) This test checks if ECM is able to respond to a rich condition caused by choking the engine. If ECM responds, problem is a lean engine condition, NOT ELECTRICAL.
- 3) This step puts a rich O2 signal (about one volt) into terminal No. 9 of ECM. Dwell should increase (lean command).
- 4) On 1987-1988 5.0L (VIN G/H) and 5.7L (VIN 6) B & F Body, (TSB No. 88-445-6E, December,1990). If dwell increases to greater than 45 degrees with heavy choking, fault is an air leak, since ECM was able to respond. If air is going to exhaust ports, disconnect solenoid(s) for the air control valve. If air still goes to ports, valve is faulty. On all others, If dwell increases to greater than 50 degrees with heavy choking, fault is an air leak, since ECM was able to respond. If air is going to exhaust ports, disconnect solenoid(s) for the air control valve. If air still goes to ports, valve is faulty.