2018 Silverado 5.3 32,000mls threw code p06dd week after dealer oil change. Next day it was gone. Started researching, checked oil added a quart. Code has not come back. It has been a week, now at 33,339mls. Im noticing that my pressures drops to about 17psi at idle when fully warm after about 30 minutes of driving Sits around 35 to 40 while driving and will go up to 70 while passing.(in Michigan) Some say this is normal with the dual stage oil pump. Im not used to Chevys, coming from owning Chargers for the last decade. i dont hear any difference in the engine sound or any weird noises. Thoughts