Lexus GX470 VSC and engine lights on dashboard with error codes P0420 and P0430 on Lexus GX470

Some Lexus GX470 owners report experiencing dashboard illumination of the VSC and engine lights along with error codes P0420 and P0430, indicating potential issues with the catalytic converter and sensors. These error codes suggest problems with catalyst system efficiency below the threshold in both Bank 1 and Bank 2. Common symptoms include the check engine light activation, which can be triggered by various factors such as a faulty catalytic converter, oxygen sensors, or air-fuel sensors. Owners may notice reduced fuel efficiency due to inefficient combustion linked to a malfunctioning catalytic converter. It is recommended that a professional diagnostic check be performed to accurately identify the cause and determine necessary repairs, which may involve replacing the catalytic converter, sensors, or addressing other related issues. Consulting a qualified mechanic or Lexus dealership is advisable for those unsure about how to proceed with repairs related to these error codes.