Join Ron Ananian The Car Doctor™ in the shop as he diagnoses two EVAP system malfunction codes, P0456 and P0457, on a 2007 Dodge Caravan. Ron digs in and finds that the vehicle has a small EVAP leak. An examination of the purge valve (which is normally closed and electrically-driven open) shows some vacuum pull on the vacuum gauge. Ron discovers that the purge valve is defective and leaking, causing the EVAP code. After installation of a new purge valve, Ron demonstrates that the closed valve no longer shows any vacuum on the gauge.