I wouldn't worry about that gunk on the oil cap unless it's showing up in the oil on your dipstick as well. I do not think it's related to the code.
I'd listen to NG as well as strongly recommend you kill VCM if you haven't just cause it's a terrible technology that everyone should get rid of if they care about their engine.
I'd listen to NG as well as strongly recommend you kill VCM if you haven't just cause it's a terrible technology that everyone should get rid of if they care about their engine.