Question

2000 Chevrolet Cavalier 2.2L with DTCs codes p0300 and p0202, what should I do?

Answer 1

P0300 Random misfire

P0202 Injector #2 open or shorted to voltage

Any injector driver circuit open or shorted to voltage will also set a random misfire, The first is to make sure the injector connection are clean and no corrosion in there, Replace the faulty fuel injector  If the fuel injector that is non operational is not resolved in a timely matter the ECM driver circuit will fail due to a faulty fuel injector.

Answer 2

P0202 CHEVROLET Code - Injector 2 Control Circuit
Read more: https://www.autocodes.com/p0202_chevrolet.html

P0300 CHEVROLET Code - Cylinder Misfire Detected Random Cylinders
Read more: https://www.autocodes.com/p0300_chevrolet.html