P0155
O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)
Description
O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1). This powertrain diagnostic trouble code covers the engine, the fuel and ignition systems, emission control and the transmission.
OBD Codes Details
Possible Causes
Faulty sensor, intake leak, clogged fuel filter, weak fuel pump, damaged wiring
Solution
Check for intake leaks, inspect and clean the sensor, measure fuel pressure, compare live data against the expected range
Symptoms
- Check engine light illuminated
- Rough idle or hesitation
- Poor fuel economy
- Engine running rich or lean intermittently on bank 2
- Failed emissions test
Diagnostic Recommendations
- Inspect O2 sensor wiring and connector for bank 2 sensor 1
- Test O2 sensor signal voltage with a scan tool
- Check for exhaust leaks upstream of the sensor on bank 2
- Verify sensor heater circuit resistance
- Replace O2 sensor if readings are out of range
Repair Cost Estimate
- O2 sensor replacement (upstream, bank 2): $150-400
- Wiring/connector repair: $80-200
- Exhaust leak repair: $100-300
- Diagnostic scan: $80-150
- Total diagnostic and repair: $150-700
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Fact-checking completed
Verified by:
Pavel Volkov
Created:
Information verified against official sources
Official Sources
Society of Automotive Engineers
Official OBD-II diagnostic trouble codes standard (SAE J2012)
Automotive engineering standards organization
International Organization for Standardization
International standard for vehicle diagnostic systems
International standards for automotive diagnostics
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