Is the buyer obliged to pay a traffic violation on the car that occurred before he bought it, knowing that the seller had provided a certificate of clearance?

The one responsible for the traffic violation is the one in whose possession it occurred, and he is obligated to pay for it. In this case, as long as the date of the violation shows that it occurred while the seller owned it, he is the one who bears it, and the certificate of clearance does not absolve him as long as the violation is established against him.