What can cause a p0008 obd code?

What is your question?

Presented originally with p0017 code as well. Had timing chain replaced and the p0008 code still exists. So far the camshaft adjuster solenoid, timing chain, and the crankshaft position sensor and one of the camshaft position sensors have been replaced. My mechanic says the other sensors look good.

What makes this problem better or worse?

Nothing, just error code

How long has your 2010 GMC Acadia had this problem?

3 weeks