* P1151: This code indicates a lean condition detected by the oxygen sensor in Bank 1. This usually means the sensor is detecting too much oxygen in the exhaust, suggesting the engine is running too lean (not enough fuel).
* P1131: This code refers to a malfunction in the air/fuel ratio sensor (often called an oxygen sensor, but it's a more sophisticated sensor) in Bank 1. This sensor is crucial for precise fuel mixture control. A faulty sensor can cause a lean condition leading to P1151.
What needs fixing:
The most likely culprits are:
* Bank 1 Upstream Oxygen Sensor (O2 Sensor): This is the sensor most directly related to these codes. It's located in the exhaust manifold before the catalytic converter. Replacement is usually the first step.
* Bank 1 Air/Fuel Ratio Sensor (AFR Sensor): If the upstream O2 sensor is okay, the problem might be the more sophisticated AFR sensor. It's also located in the exhaust manifold. This sensor is more expensive to replace than a standard O2 sensor.
* Vacuum Leaks: A vacuum leak in the intake system can cause a lean condition, which then triggers these codes. This requires thorough inspection of all vacuum hoses and connections.
* Mass Airflow Sensor (MAF Sensor): A faulty MAF sensor can lead to incorrect air measurements, causing an improper fuel mixture and throwing the codes.
* Wiring/Connectors: Damaged wiring or connectors to the O2/AFR sensors can also be a problem.
Are these parts under warranty?
Absolutely not. A 2001 vehicle is far beyond any manufacturer's original warranty. Extended warranties might cover some repairs, but that depends on the specific terms of the extended warranty you might have purchased separately. You'd need to check the details of your extended warranty policy to see if it includes these repairs.
Recommendation:
Have a qualified mechanic diagnose the problem accurately. While replacing the Bank 1 upstream O2 sensor is a common first step, addressing underlying issues like vacuum leaks is crucial to prevent recurring problems. A simple replacement without proper diagnosis could lead to further damage or unnecessary expenses.
