Mazda DTC P1138 – HO2S Bank 1 Sensor 2 Signal Above 0.45v (A/F Ratio Too Rich)
DTC P1138 meaning on Mazda
DTC P1138 on a Mazda indicates that the Heated Oxygen Sensor (HO2S) Bank 1 Sensor 2 signal is reading above 0.45 volts, signaling that the air-fuel ratio is too rich.
Mazda DTC P1138 symptoms
Symptoms of DTC P1138 on a Mazda may include:
- Check Engine Light illuminated
- Decreased fuel efficiency
- Engine running rough or misfiring
Mazda DTC P1138 causes
Common causes of DTC P1138 on a Mazda include:
- Faulty Heated Oxygen Sensor (HO2S) Bank 1 Sensor 2
- Vacuum leaks
- Fuel pressure too high
- Exhaust system leaks
Mazda DTC P1138 seriousness
DTC P1138 should be addressed promptly as it can lead to decreased fuel efficiency and potential engine performance issues if left unresolved.
How to diagnose DTC P1138 on Mazda
To diagnose DTC P1138 on a Mazda, you can:
- Use an OBD-II scanner to retrieve the fault code
- Inspect the Heated Oxygen Sensor (HO2S) Bank 1 Sensor 2 for any visible damage
- Check for vacuum leaks or exhaust system leaks
- Test fuel pressure to ensure it is within specifications
How to fix DTC P1138 on Mazda
To fix DTC P1138 on a Mazda, you may need to:
- Replace the faulty Heated Oxygen Sensor (HO2S) Bank 1 Sensor 2
- Repair any vacuum leaks or exhaust system leaks
- Adjust fuel pressure if it is too high
How to erase DTC P1138 on Mazda
To erase DTC P1138 on a Mazda, you can:
- Use an OBD-II scanner to clear the fault code
- Ensure the underlying issue causing the fault code has been resolved
Recommended tools for Mazda diagnostics
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