P0132

What it means

P0132 means the engine control unit has seen a voltage from the Bank 1 Sensor 1 oxygen sensor (upstream, before the catalytic converter, on the bank containing cylinder 1) that stays higher than expected. The signal is stuck high, typically above about 1.0 V, or does not drop as it should when the mixture goes lean. The cause may be the sensor, a short in its wiring, or a real fuelling fault, so it needs checking in that order.

Symptoms

• Engine management light on
• Poor fuel economy
• Rough idle or hesitation
• Black smoke or a strong smell of fuel from the exhaust
• Possible failed emissions test
• Engine running rich or in fuel limp-home strategy

Possible causes

• Faulty or contaminated upstream oxygen sensor (Bank 1 Sensor 1)likely
• Signal wire shorted to voltage or to another circuit, or damaged wiring harnesslikely
• Corroded, damaged or loose sensor connector terminalspossible
• Genuine rich running caused by a leaking or stuck-open injector, high fuel pressure or a faulty fuel pressure regulatorpossible
• Faulty airflow or manifold pressure sensor, or coolant temperature sensor giving wrong readings, causing over-fuellingpossible
• Sensor contaminated by silicone, coolant or oil from an engine faultrare
• Fault in the engine control unit sensor circuitrare

How to diagnose

1. Read all stored and pending codes and the freeze frame data, noting engine temperature, load and fuel trim values at the time the code set.
2. Check for other fuelling codes (misfire, MAF, MAP, coolant temperature, fuel pressure) and deal with those first if present.
3. Inspect the sensor wiring and connector for chafing, heat damage, water ingress, corrosion and bent or pushed-back terminals, especially near the exhaust.
4. With the engine warm, view live data for the Bank 1 Sensor 1 voltage and fuel trims. A voltage stuck high with trims pulling fuel out suggests a real rich condition, while a stuck voltage with normal trims points to the sensor or wiring.
5. Unplug the sensor and check the signal and reference circuits for a short to voltage or to each other, and check the heater circuit supply and earth as the model requires.
6. Check the sensor for contamination or damage, and look for signs of coolant, oil or fuel contamination in the exhaust.
7. If a rich condition is suspected, check fuel pressure, injector leakage, the airflow sensor reading and the purge valve operation to the manufacturer's specification.
8. Check live sensor response by creating a temporary lean condition, such as a small controlled vacuum leak or snapping the throttle, and see whether the voltage drops and recovers quickly.

How to fix

• Repair or replace damaged wiring, and clean or replace faulty connector terminals.
• Replace the upstream oxygen sensor if it is slow, stuck or contaminated, using the correct type for the engine.
• Repair any genuine rich-running fault found, such as a leaking injector, faulty fuel pressure regulator or purge valve.
• Replace faulty airflow, manifold pressure or coolant temperature sensors that are causing wrong fuelling.
• Find and cure the source of any contamination, such as an oil or coolant leak, before fitting a new sensor.
• After repair, clear the code and road test, confirming that the sensor voltage switches normally and fuel trims settle.

Can I keep driving?

Nearby codes

• P0131GenericO2 Sensor Circuit Low Voltage Bank 1 Sensor 1
• P0133GenericO2 Sensor Circuit Slow Response Bank 1 Sensor 1