Toyota Trouble Code P1133 and Generic Trouble Code P0133, indicate trouble with the air/fuel ratio sensor located on bank one (1) of your Toyota Camry's engine. The air/fuel ratio sensor is responsible for measuring oxygen levels in your car's exhaust and reporting this data to the engine control module (ECM); for correct computation of fuel delivery. This sensor's duty is similar to that of the oxygen sensor on older model vehicles. Bank 1 is the side of the engine where the number 1 cylinder is located.
Toyota Trouble Code P1133 (P0133 Generic OBDII) may indicate one or more of the following has happened:
- The Bank 1 air/fuel ratio sensor is faulty.
- The wiring to the air/fuel ratio sensor is broken.
- The engine has a large exhaust leak.
In this specific case, since the check engine light turns back on immediately after resetting it, it would be safe the say the problem is a Hard-Fault, meaning it is constant. We suspect this problem is more than likely due to a defective air/fuel ratio sensor, or damaged wiring and/or wiring harness.
In our opinion, the best option would be to have your Toyota Camry checked out by a smog check repair station to verify this before spending the money to replace it. The station will charge a fee for their diagnosis, which should be less than what it could cost if you were to replace working components.