I have been running a bottle of fuel injector cleaner thru at about every 8k miles and also use Chevron gas.(top Tier) and also use Shell from time to time (also top tier)
I have been using the 3M brand fuel injector cleaner but will switch to the Techron

Not that it matters but here are some links,

Amazon reviews
http://www.amazon.com/review/product...owViewpoints=1

Wikipedia
http://en.wikipedia.org/wiki/Techron

EDIT and one more from another forum

http://www.nissanforums.com/truck-su...ntrations.html

 

not specific to your issue; but just a general question... the DIC tells you if its 4 cyl or in 8 mode right?

say your cruising along... 50 MPH in V4.... then you turn on the A/C....

can it run just in 4, or does the A/C need all 8?

just wondering!

 

Under some conditions, the A/C w/ drop it out of V4 mode. All depends on the load on the engine.

 

Yes I had this same problem and I just bought my 2018 Silverado. The serviceguy said that it was completely normal... I said nooooo it’s not normal test it again... sure enough it was a problem with the exhaust damper. This he said caused the wrong compression and everything was getting out of whack. Note this is only 3 years old I’m afraid of other problems that will arise after my warranty is over.