Hi Seed Guy.
Did you ever get an answer to your question?
I THINK it works like this:
Code NAA is FEDERAL emissions.
Code NAE is CALIFORNIA emissions.
Code YCH is WAIVER TO FEDERAL emissions.
Code YCF is WAIVER TO CALIFORNIA emissions.
When Code NAA is used the truck must have a destination dealership NOT IN California.
When Code NAE is used the truck must have a destination dealership IN California.
When Code YCH is used a truck can be delivered to California WITH FEDERAL EMISSIONS, Code NAA, for export to another state. It cannot be registered in California.
When Code YCF is used the truck is equipped with CALIFORNIA EMISSIONS, Code NAE, even though it will be delivered to a dealer not in California.
The YCF/NAE code is useful for people who live in parts of California that make it more practical for them to do business in a bordering state yet be able to register their vehicle in California.
The YCH/NAA code gives dealers in California a chance to get out-of-state business.
YOU SHOULD NOT HAVE TO ORDER THE YCF/NAE EMISSIONS OPTION UNLESS OREGON STATE LAW HAS ADOPTED TIGHTER THAN FEDERAL EMISSIONS STANDARDS.
All this would be flawless (free trade for everyone) except the YCF/NAE code is only available in the bordering states and a few others. Sounds like some protectionist tactics to keep Californian's somewhat limited in where they can purchase from from. If I were Frahm Dodge in Norco, CA and asking 3K-5K over sticker just for "Dealer Mark-Up" I'd want some protection too.