Code 44, Lean Exhaust Indication
NOTE:
Test numbers refer to test numbers on diagnostic chart.
- System will return to "open loop" if O2 sensor cools off while engine is idling. Scan "loop" status often during testing. For intermittent condition, see INTERMITTENTS in TESTS W/O CODES article.
- Check 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.
- Placing a high impedance (10-megohm) digital voltmeter in series between the battery and the Purple oxygen sensor lead to the ECM will put a rich O2 signal (about one volt) into terminal No. 9 of ECM. Dwell should increase (lean command).
- 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. Repair exhaust leaks as necessary. If no exhaust leaks are found, service carburetor.