Making sense of error codes 2001 S80

[rb61]

First error (engine light) indicated 02 sensor. Had that cleared.
Second appearance of error indicated cam position sensor. Had that cleared.
Third appearance of error indicated P1330 CVVT.
Can someone help me understand this issue? Can a bad 02 sensor cause additional errors that may not be bad parts/sensors? Where should I start?

Vehicle seems to run fine, but gas milage has dropped dramatically.


This all happened within 2 weeks.

Thanks