07 pineapple belt 1.4 has an engine failure light?

07 pineapple match 1.4 has engine failure light. Seven Polo 1.4 engines have strong power and low fuel consumption. Equipped with 1.4 naturally aspirated engine and engine fault light. Polo shows that the engine fault light is on because the throttle valve is too dirty and the mixture is too rich. Excessive carbon deposition in the engine leads to unqualified exhaust emission. Engine oxygen sensor fault.