I will be flying direct from Chicago to Frankfurt; will have a 2 hour & 10 minute layover in Frankfurt until my flight to Porto, Portugal. Question is whether I have to go thru customs in Germany (and is 130 minutes enough time?) or will I go thru customs in Porto?
Same answer as in your other thread: https://community.ricksteves.com/travel-forum/germany/customs-and-layover-in-frankfurt-airport
1) It is not customs that matters, it is immigration (passport control).
2) Both Germany and Portugal are in the Schengen Area, so you are entering the Schengen Area in Frankfurt and that is where you will go through immigration
3) Is this one ticket or two? If it is one ticket, they would not have sold you the ticket if that was not enough time to go through immigration.
Customs is the check on goods, the contents of your luggage. It is a random stop only, takes zero time and will happen after you finally pick up your bags, i.e. in Porto.
Is this one ticket or two?
To make sure this key issue Chris F brought up does not get lost/overlooked, I am making this post
This is the critical question relative to 'enough time?"; If two tickets and checked bags to deal with, life will become "interesting".
Immigration/ Passport control is what you need to be concerned with. Customs is more a factor returning to US if you bought a lot of valuables abroad and exceeded your limit thus needing to pay a tariff.