P2197 Fault Code

O2 Sensor Signal Biased/Stuck Lean Bank 2 Sensor 1

• What does that mean?
• Symptoms
• Causes
• Solutions

The P2197 fault code indicates that the O2 sensor on Bank 2, Sensor 1 is reporting a lean condition. This means that the sensor is detecting too much oxygen in the exhaust compared to the expected levels.

• Bank 2 refers to the side of the engine that is not aligned with the engine's front.
• Sensor 1 typically refers to the oxygen sensor located before the catalytic converter.

What are the symptoms of the P2197 code?

When experiencing the P2197 code, the following symptoms may be observed:

• The Check Engine Light (CEL) illuminated on the dashboard.
• Poor engine performance including a rough idle.
• Decreased fuel efficiency.
• Possible hesitation or stalling during acceleration.
• Excessive emissions due to improper air-fuel mixture.

What causes the P2197 code?

There are several potential causes for the P2197 error code:

• A faulty O2 sensor that is providing inaccurate readings.
• A vacuum leak in the intake system, allowing excess air to enter.
• A leak in the exhaust system before the O2 sensor, which can affect the readings.
• Fuel system issues such as low fuel pressure or a failing fuel pump.
• Problems with the engine control unit (ECU) that may lead to incorrect mixture adjustments.

How to fix P2197?

To resolve the P2197 code, consider the following steps:

• Use an OBD-II scanner to confirm the error code and perform a visual inspection of the O2 sensor and connections.
• Check for any vacuum leaks around the intake manifold and replace any faulty hoses.
• Inspect the exhaust system for leaks, particularly near the O2 sensor.
• If the sensor is confirmed to be faulty, replace the O2 sensor.
• Ensure the fuel system is operating properly by checking for proper fuel pressure and diagnosing the fuel pump if necessary.
• Clear the fault codes and test drive the vehicle to see if the check engine light returns.