Leak detection pump.
It might be an exhaust leak
probably a fuel leak somewhere .
The obvious answer would be that there would be a leak somewhere...
Trouble code P0442 means: Evaporative Emission System Leak Detected (small leak)
Because the leak is high up in the tank.
There shouldn't be, but if you do, that indicates an oil leak somewhere
possible faulty leak detection pump
Trouble code P0455 means: Evaporative Emission System Leak Detected (gross leak/no flow)