P1135 Fault Diagnosis and Repair on 2001 Toyota Tacoma
The P1135 diagnostic trouble code on a 2001 Toyota Tacoma refers to an issue with the Air Fuel Metering Sensor, which is located on the intake manifold. This sensor plays a critical role in monitoring air-fuel mixture for optimal engine performance and fuel efficiency. After replacing the Mass Airflow (MAF) sensor and resetting the system, the P1135 code returned after approximately one minute of driving—indicating a recurring issue. While vehicle performance remains stable, fuel economy has noticeably decreased. The root cause appears to be either a defective replacement MAF sensor or an electrical circuit fault in the Air Fuel Metering Sensor circuit. Testing the circuit integrity is essential; if the MAF sensor is new and the code persists, it suggests that either the part itself is faulty or there's a wiring or connection issue. This experience may help other owners of 2001 Toyota Tacomas experiencing similar P1135 issues after MAF sensor replacement.
What was the final solution? Was it a new oxygen sensor or another component?