Error Code P0455 (Emission, detected Large Leak) Need help pinpointing
 

I have a check engine light for the P0455 emissions code. I'm trying to narrow down the issue quickly since I have to get an inspection and renew my registration within the next month. (Wont pass with the emissions code)
-I've already replaced the gas cap.
-Unable to find any obvious vacuum leaks
-Does the light automatically turn off when the problem is fixed or does it need to be reset and driven for a while for the system to determine whether the problem has gone away?
Any input would be greatly appreciated!

Check the hoses at the charcoal canister

Other points to check.
vent hose on top of the tank
small link of hose back by the fuel filter.

Is there any good way to check the vent hose without having to drop the tank?

The modern way is with a smoke machine.

Most good repair shops should have one right? Any guess on an approximate cost? (Just to find the leak, not to fix it)
PS. Didn't I buy a radiator fan from you a few months back?

Yep that was me. I don't ever go to a shop so I have no idea how much EVAP troubleshooting they do. I have been tempted to get one myself. I'm tempted that way about any tool, ha ha.

Free at the dealer.

'99 S70 GLT with P0455 hasn't been located, yet.
 

I've checked and replaced various hoses related to the canister but have not replaced the purge valve. A local shop will run full diagnostic for $99.99 that gets included in the repair bill if the work is done there, That's the next step but I'll do the work myself with FCP euro parts.