Download Introduction Under certain driving conditions, some 1997 – 1999 5S-FE California emission specification Camrys and 1999 5S-FE California emission specification Solaras may exhibit a M.I.L. “ON” with DTC P1133 (Air Fuel Ratio Sensor Slow Response Malfunction). An improved Air Fuel Ratio (A/F) Sensor was developed to correct this condition (See TSB EG006-99). In some rare cases, P1133 may still set after the improved A/F sensor is installed. The Engine Control Module (ECM) logic has been modified to correct this condition. Applicable Vehicles Top – Vehicle Technical Service Bulletins. Customer Interest . .MIL ON – DTC P1133 Updated (Oxygen Sensor Circuit) . Notes ^ 1997 – 1999 model year Camrys with 5S-FE California emission specification. ^ 1999 model year Solaras with 5S-FE California emission specification. Repair Procedure 1. Should a M.I.L. “ON” condition with P1133 be encountered, perform diagnostic procedures as described in the Repair Manual. 2. If the problem source cannot be identified after checking all affected areas according to the Repair Manual, the cause may be an A/F Sensor or ECM logic malfunction. In this case, follow the procedure in the flowchart shown to determine which part needs to be replaced.