The contact owns a 2012 Chevrolet Equinox. The contact stated that while starting the vehicle, the engine revved up abnormally. While driving at various speeds, there was a humming sound coming from the underbody of the vehicle. The check engine warning light was illuminated. The vehicle was taken to a certified mechanic who diagnosed that the catalytic converter had failed, the throttle body failed, and the exhaust manifold had fractured. The vehicle had not been repaired. The manufacturer was made aware of the failures and confirmed there was no recall on the VIN. The failure mileage was 137,000.