How to Fix P1130 Code in 2000 Toyota Tundra 3.4L V6: Air/Fuel Sensor Diagnosis
I own a 2000 Toyota Tundra with a 3.4L V6 engine. After replacing my stock paper air filter with a K&N filter, my check engine light activated approximately one week later. The diagnostic tool revealed code P1130. P1130 is an oxygen sensor-related fault code for Bank 1 Sensor 1 — specifically an air/fuel ratio sensor. While this sensor functions differently from standard oxygen sensors, it plays a critical role in monitoring the air-fuel mixture. I'm wondering if the K&N filter installation could have caused or contributed to this issue. Are there other possible causes? Any insights or troubleshooting steps would be greatly appreciated.
P1130 is an air/fuel ratio sensor code for Bank 1 Sensor 1, which commonly fails in vehicles like the Toyota Tundra. If you suspect the new K&N filter as a cause, try reverting to the original paper filter and monitor if the check engine light returns — this will help isolate whether the filter or the sensor is at fault. A reasonable assumption is that the air/fuel sensor itself has failed and needs replacement. To confirm, you should obtain the exact specifications for your vehicle's sensor and perform a functional test. Note: This sensor differs from standard oxygen sensors in operation. Ensure you purchase the correct part — compatibility may vary based on whether your Tundra meets Federal or California emissions standards. For reliable parts, consider purchasing directly from a Toyota dealership or an authorized parts supplier with emission-specific expertise. You can also remove the sensor and read its part number to cross-reference with aftermarket brands. Please update this thread once you've completed testing or repairs.