DTC P0132 – O2 Sensor Circuit High Voltage (Bank 1 Sensor 1).

This code means the upstream oxygen sensor (before catalytic converter) is sending a high voltage signal (usually > 0.9V) to the ECU.

✅ P0132 – Meaning

Bank 1 Sensor 1 O2 sensor voltage too high (rich condition or electrical fault).

✅ Common Symptoms

High fuel consumption

Black smoke

Rough idle

Strong fuel smell

Hesitation on acceleration

Sometimes no symptoms other than Check Engine Light

✅ Possible Causes

1. Rich Running Condition

Leaking fuel injector

Fuel pressure too high

Faulty fuel pressure regulator

Stuck open purge valve (EVAP purge solenoid)

2. O2 Sensor Issues

Sensor internally shorted

Contaminated O2 sensor (fuel, coolant, oil)

3. Wiring / Connector Problems

Short-to-power in O2 signal wire

Melted wiring near exhaust

Bad ground or reference wire

4. ECU Issues (rare)

Internal fault causing incorrect voltage reading

🔧 Step-by-Step Diagnosis for Workshop

1. Check Live Data

Look at Bank 1 Sensor 1 voltage:

Normal: 0.1V – 0.9V switching

Fault: Stuck high 0.9–1.2V

If stuck high → continue.

2. Inspect Wiring & Connector

Check the harness from sensor to ECU:

Burn marks

Melted insulation near exhaust

Loose or corroded connector

Signal wire touching 12V supply

Repair any damaged wiring.

3. Check Sensor Heater

A failed heater can cause incorrect sensor output.

Check:

Heater resistance (typically 5–14 ohms)

Power supply (12V)

Ground continuity

4. Test Fuel System (for rich condition)

If wiring and sensor are OK:

💥 Check fuel pressure

Too high pressure → rich mixture → high O2 voltage.

💥 Check injectors

Leaking injector

Stuck open injector

💥 Check EVAP purge solenoid

If stuck open → fuel vapors enter intake → rich condition.

5. Replace O2 Sensor (if faulty)

If:

Wiring OK

Fuel trims normal

Sensor voltage stuck high

→ Replace Bank
Sensor 1 O2 sensor.

🛠 Recommended Repair Order (Quick)

1. Scan live data

2. Inspect wiring & connector

3. Check sensor heater

4. Test fuel pressure & injectors

5. Replace O2 sensor if needed

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