Primary Heated Oxygen Sensor Circuit Range/Performance (Honda)
What does P1149 mean?
The P1149 code means the vehicle's onboard diagnostic system has detected: Primary Heated Oxygen Sensor Circuit Range/Performance (Honda). This is a moderate severity code.
Common Symptoms
- Check Engine Light on
- Poor fuel economy
- Failed emissions test
- Rough idle
- Hesitation during acceleration
Probable Causes (Ranked by Likelihood)
- Failing primary oxygen sensor (air-fuel ratio sensor) Very High
- Exhaust leak before the primary sensor High
- Vacuum leak causing lean condition Moderate
- Fuel system issue (dirty injectors or weak fuel pump) Moderate
- Wiring or connector damage to the primary O2 sensor Low
Step-by-Step Diagnostic Procedure
-
Monitor the primary O2 sensor (Sensor 1) data with a scan tool
-
Check for exhaust leaks at the exhaust manifold and downpipe
-
Inspect for vacuum leaks using a smoke machine
-
Test fuel pressure to ensure adequate fuel delivery
-
Replace the primary O2 sensor if response is slow or erratic
Frequently Asked Questions
What does P1149 mean on a Honda?
P1149 indicates the primary heated oxygen sensor (also called the air-fuel ratio sensor) is not performing within expected parameters. This sensor is critical for precise fuel mixture control on Honda vehicles.
Is the Honda air-fuel ratio sensor different from a regular O2 sensor?
Yes. Honda uses a wideband air-fuel ratio sensor as the primary sensor (Sensor 1). It provides more precise readings than a traditional narrow-band O2 sensor and is more expensive to replace.
How much does a Honda air-fuel ratio sensor cost?
Honda OEM air-fuel ratio sensors typically cost $150 to $300 for the part. Aftermarket options range from $80 to $200. Using an OEM or high-quality brand is recommended for Honda vehicles.