Will an exhaust leak make my check engine light come on?

Yes, an exhaust leak can make your check engine light come on. While not always guaranteed, a significant exhaust leak can trigger the light because the oxygen sensors detect an imbalance in the exhaust gases. This imbalance is often due to unmetered air entering the exhaust system after the sensors. The computer interprets this as a problem and illuminates the check engine light. The specific code that's triggered will vary depending on the severity and location of the leak.