Alarm Anticontamination Alarm in Peugeot 206

Good morning
I have a Peugeot 206 1.6 of 2006 the problem begins with the anomaly's anti -antamination anomaly indication after 2 days and several km showed me the catalyst fault and in the panel the motor light is always on and every time I turn on the car the alarm.
I have reviewed almost everything and make a change of spark plugs cleaning butterfly and MAP sensor that could be the most that would have to check ??

kind regards