Do i need to unlock phaser gear on 4.0L and how to test

[edlobsta]

i recently acquired a 06 xterra that is supposed to need the vvt cam sprockets replaced. I amakeptical of that assessment because it was at a shop and the guy that owned the truck was incredibly unmechanical! Also because the timing chain tensioners are both (r&l top) worn down completely through the plastic and well into the metal plunger shafts. Plus all the other guides are worn a great deal also. I think the shop was trying to pad the bill. The truck only has 120,000 miles. I just don't want to spend an extra 400$ or so if I don't really need/have to. If I could maybe "unlock " these, I could try and determine if they are still good. Is it possible that the damaged tensioner guides, worn guides and possible chain slack could cause the same symptoms/codes as the vvt gears?
Thanks for the help

[edlobsta]

Anyone??