P0455 DTC on 01 S430
 

Hi everyone,

Working on a check engine light with a p0455 dtc. No need to explain the code as I am a 13 yr Master Tech. Just don't have a MB scan tool and smoke machine in my garage. Other than disconnected hoses, are there any other "common" issues generating this trouble code. Fuel cap and seal appear ok, can't smell fuel, or see any obvious hoses disconnected. Suspecting a vent valve/solenoid or purge valve issue but just doing off past experiences. Any one with insight on this issue??
Thanks in advance!