$1,600 is ridiculous. Find a new shop. This kind of shop is just about overcharging...period.

There are links on the forum for the factory shop manual. The manual shows what is necessary in a 16k service.

As mentioned, a CCT replacement/install shouldn't cost all that much. This shop telling you otherwise, again, proves they're overcharging.

Valve check doesn't equal valve adjustment. As already noted, you may not even need it. Many shops will want to automatically replace the valve cover gasket. Again, not always necessary.

The rest of the 16k service is basically a tune-up.