Jenga

1 psi/second, down to about 5, then will lose at a much slower rate. With the oil filler cap on, air leaks from the rear of the passenger head--am totally sure of this. Recently, the car will not start at all, with spark and fuel present, but no CEL's. Don't think that these two are related, but maybe they are?

quickaudi:STFA

if it's leaking from the rear of the passenger head, where exactly is it leaking?

Jenga

From a "cavity" directly behind the camshaft actuator (or whatever that is) on rear of head.

quickaudi:STFA

as in your cam seals?