Take out the downstream O2 sensor and spray some silicone spray on it.. That'll throw a P0430 code right away for you! Kidding.. although that will work. Silicone kills CC's and O2 sensors on contact.
Other than that, living in CT covers you for 15yrs/150Kmi.
FWIW, the used 2002 Forester with ~150Kmi on it my brother recently picked up came fully equipped with a P0430 code, EVAP system codes and a rotted out rear subframe!