2012 Mazda MAZDA6 Engine problems

While vehicle is in motion the gear indicator on the dash I will flash in and out. When the light goes out the vehicle will stall and when it comes back on the vehicle will rev up causing an unsafe speed. The ecm was replaced and two months later the problem still persists. The dealer cannot find anything wrong

Tl* the contact owns a 2012 mazda 6. While driving approximately 55 mph, an abnormal sound emitted from the engine compartment. The failure recurred multiple times. The vehicle was taken to a dealer for diagnostic testing. The technician diagnosed that the catalytic converter seal ring needed to be replaced. The failure recurred. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 42,000.

Tl* the contact owns a 2012 mazda mazda6. The contact stated that while unoccupied, the vehicle rolled away and crashed into a wall while the emergency brake was engaged. The contact also stated that the check engine light illuminated and the vehicle had difficulty starting. The vehicle was taken to the dealer where the failure could not be replicated. The vehicle was not repaired. The failure mileage was not available.