Toyota Corolla Cross: Vehicle Exterior

 How To Proceed With Troubleshooting

CAUTION / NOTICE / HINT HINT: *: Use the GTS. PROCEDURE 1. VEHICLE BROUGHT TO WORKSHOP NEXT 2. CUSTOMER PROBLEM ANALYSIS HINT: In troubleshooting, confirm that th

 Catalyst System Efficiency Below Threshold Bank 1 (P042000)

MONITOR DESCRIPTION The ECM uses air fuel ratio sensors mounted in front of and behind the Three-Way Catalytic Converter (TWC) to monitor its efficiency. The first sensor, the air fuel ratio sensor (sensor 1), sends pre-catalyst information to the ECM. The second sensor, the air fuel ratio sensor