My 2017 Volt reported a ‘Propulsion Power is Reduced’ message on the display. When I took the car to the dealership for service, they stated that a new EGR valve was needed. The part alone is $1847. The total service with labor would have been over $3000. Looking online, it is a very common issue for the gen 2 Volts. Unfortunately, the dealership is saying this repair is not covered under warranty.