Code 44
Code 44 is a diagnostic trouble code related to a lean exhaust indication on the Pontiac Fiero.
Code 44 indicates that the ECM is seeing an oxygen sensor signal that suggests the engine is running lean.
Overview
The Oxygen sensor monitors oxygen content in the exhaust. The ECM uses this signal to adjust fuel mixture during closed-loop operation.
Code 44 is set when the ECM detects a lean exhaust condition for longer than expected. A lean indication can be caused by too much air, too little fuel, an exhaust leak, a sensor problem, or an electrical issue.
Flash pattern
Code 44 is displayed as:
- Four flashes
- Pause
- Four flashes
This represents code 44.
Animated flash pattern:
Meaning
Code 44 usually indicates that the ECM sees the exhaust mixture as too lean.
Possible causes include:
- Vacuum leak
- Low fuel pressure
- Weak fuel pump
- Restricted fuel filter
- Dirty or restricted injectors
- Exhaust leak before or near the oxygen sensor
- Faulty oxygen sensor
- Oxygen sensor wiring problem
- Poor ground or connector problem
- MAP sensor problem
- ECM input problem
Symptoms
Possible symptoms may include:
- Check engine light
- Hesitation
- Poor acceleration
- Surging
- Rough idle
- Stalling
- Higher engine temperature
- Spark knock or pinging
- Poor drivability
- Little or no obvious drivability problem
Diagnosis
Basic diagnostic checks include:
- Confirm that Code 44 is present.
- Check for Vacuum leaks.
- Inspect the oxygen sensor wiring and connector.
- Check for exhaust leaks near the oxygen sensor.
- Check fuel pressure.
- Inspect or replace the fuel filter if restricted.
- Check fuel pump operation.
- Check for injector problems.
- Check for other stored trouble codes.
- Check MAP sensor vacuum and wiring.
- Check grounds and ECM connections.
Vacuum leaks
A vacuum leak can allow extra unmetered air into the engine, causing a lean condition.
Related topics:
Fuel delivery
Low fuel pressure or restricted fuel delivery can cause the engine to run lean.
Related topics:
- Fuel pressure test
- Fuel pump problems
- Fuel filter replacement
- Fuel injectors
- Fuel pressure regulator
Oxygen sensor and exhaust leaks
An oxygen sensor problem or exhaust leak near the sensor can cause the ECM to see a false lean condition.
Related topics:
Related codes
Related fuel-control and oxygen-sensor codes include:
Notes
Code 44 should not automatically be treated as a failed oxygen sensor. Vacuum leaks, fuel pressure problems, exhaust leaks, wiring faults, and sensor issues can all cause a lean indication.
Diagnosis should determine whether the engine is actually running lean or whether the ECM is receiving a misleading signal.