PO455 small leak detected at vent solenoid (above fuel tank) of my "04 Buick Rendezvous 3400

Question

My mechanic wants to see diagram of evap system of my 2004 Rendezvous 3400

Answer 1

P0455 Evaporative system large leak detected

This code , if there is a large evap leak you check the fuel cap there is a seal there is it is worn replace, or just replace the fuel cap. With a large leak  evap code you can smell the fuel, and in many cases with a evap smoke  test the system passes, What happens  in many of these cases is  the fuel tank pressure sensor sends incorrect vacuum / pressure.