2002 Chevy Malibu - purge valve selonoid

if gm told you that only the gas cap or purge solenoid could be the problem......they are wrong.could be a large leak in any of the evap lines or canister even in rare cases a leaking gas tank or a faulty fuel tank pressure sensor can trigger a false code .Best to test with a smoke machine.take a bright light and inspect all the evap lines.....besides that all you can do is start replacing things which is not the right way to do it and you could replace all components like purge solenoid,canister,gas cap and still have same problem.