P0440 GMC -what other tests besides vapor test will pinpoint the fault?

Question

Recurring PO440 code on 2001 Sonoma even after fuel fill cap replaced and retested with no further fault located.

Answer 1

P0440 Evaporative emission control system malfunction

This code condition occurs when the EVAP system can not maintain or achieve vacuum. what gives vacuum is from the purge control solenoid, Check at or around the fuel tank if anything the purge line to the fuel tank may have gotten disconnected,