• Check Engine Light is on
• Poor fuel economy
• Rough engine idle
• Faulty oxygen sensor
• Wiring issues (short to voltage)
• Faulty ECM
ECM: Engine Control Module
Oxygen Sensor: A device that measures the oxygen level in the exhaust gases
• P2257
• P0136
O2 Sensor Negative Current Control Circuit High Bank 2 Sensor 1
This code means that the car's computer is getting a signal from an oxygen sensor that is too high. It's like the sensor is shouting too loudly when it should be whispering.
The P2256 code indicates that the oxygen sensor in bank 2, sensor 1, is sending a higher than expected current signal to the engine control module (ECM).
The oxygen sensor measures the amount of oxygen in the exhaust gases and sends this information to the ECM. The ECM uses this data to adjust the air-fuel mixture for optimal combustion. A 'high' circuit condition means the sensor is sending a higher voltage signal than normal, which could indicate a fault in the sensor or the circuit.
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for damage.
• Test the oxygen sensor with a multimeter.
• Replace the faulty oxygen sensor.
• Repair or replace damaged wiring or connectors.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Wrench set
$150 - $400
Moderate
• Toyota Camry
• Honda Accord
• Ford F-150
• Regularly inspect and maintain the exhaust system.
• Ensure proper fuel quality.
• Perform regular vehicle diagnostics.
Sensor Issue
• Have the vehicle inspected by a professional if unsure.
• Avoid driving long distances until the issue is resolved.
Check with the vehicle manufacturer for specific warranty coverage on emissions components.
This code has been associated with vehicles that have higher mileage and older oxygen sensors.
Moderate – Addressing this issue soon can prevent further engine performance problems.
Driving with a faulty oxygen sensor can lead to increased emissions, which may not comply with local environmental regulations.
• Engine at operating temperature
• Vehicle in closed-loop operation
The oxygen sensor is located in the exhaust manifold of bank 2, before the catalytic converter.
Q: Can I drive my car with a P2256 code?
A: It's possible to drive short distances, but it's best to fix the issue soon to avoid further problems.
Q: How do I know if my oxygen sensor is faulty?
A: Symptoms include poor fuel economy, rough idle, and a lit Check Engine Light.
