You should find someone with a good obd2 scanner and obtain some live data and a freeze frame. Maybe check to see exactly what obd2 codes that your car is showing. Pull up the live data for the primary & secondary o2 sensors to see if they are fluctuating like how they should. The primary should be fluctuating between 0v-.9v and the secondary should have a steady constant voltage of maybe .6V or .7V. If the two oxygen (o2) sensors are showing the same voltage readings, then most likely you have a leak somewhere or a bad catalytic converter. Try to grab laser temp gun to check the temperature of the catalytic converter at normal operating temperature to see if it is operating like how it should. Diagnose before you waste money on random parts that are not the culprit to your problem.