THE CONTACT'S WIFE OWNS A 2017 CHEVROLET IMPALA. THE CONTACT STATED THAT WHILE DRIVING AT VARIOUS SPEEDS, SHE WOULD SMELL AN ABNORMAL, EXHAUST ODOR INSIDE THE VEHICLE'S CABIN WITHOUT WARNING. THE CONTACT THEN STATED THAT WHILE DRIVING AT 50 MPH, HE HAD HEARD A LOUD NOISE EMIT FROM THE ENGINE WITHOUT WARNING. THE CONTACT THEN PULLED OFF TO THE SHOULDER AND UPON INSPECTION OF THE HOOD, THE CONTACT DISCOVERED THE CATALYTIC CONVERTER HAD BROKEN OFF THE ENGINE. THE CONTACT WAS ABLE TO SLOWLY DRIVE THE VEHICLE HOME AND THEN CALLED EL DORADO CHEVROLET(2300 N CENTRAL EXPY, MCKINNEY, TX 75070) WHERE HE WAS INFORMED HIM THAT THERE WERE ZERO RECALLS ON THE VEHICLE; THE CONTACT WAS INFORMED TO BRING IN THE VEHICLE FOR INSPECTION. UPON INVESTIGATION, THE CONTACT DISCOVERED A TECHNICAL SERVICE BULLETIN NHTSA ID NUMBER:10116660 WHICH HE LINKED TO HIS FAILURE. RECENTLY, THE CONTACT'S WIFE WAS DIAGNOSED WITH LUNG CANCER AND THE CONTACT HAD LINKED THE PROLONGED EXPOSURE TO THE EXHAUST ODOR AS THE POSSIBLE CAUSE OF THE DIAGNOSIS. THE MANUFACTURER WAS NOTIFIED OF THE FAILURE AND OFFERED NO ASSISTANCE. THE VEHICLE HAD YET TO BE REPAIRED. THE FAILURE MILEAGE WAS UNKNOWN.