About to start a timing chain replacement on a 14. Is there a way to tell if the chain is bad before taking the timing cover off? I have a poor idle and throwing codes for cam crank correlation on banks 1 and 2. Looking at ordering a cloyes set from rock auto. Anyone know if there is a difference in the 3 cloyes sets they offer as far as quality. One comes just chains guides and tensioners, next one adds gears and final one adds the water pump. Also anyone have a recommendation to source phasers and oil pump? Also any other input advice or help os greatly appreciated.