I had to replace timing chain guides. It is the main chain guide that breaks and the plastic piece slides down and the main tensioner goes and hits the main chain in the wrong place. Dealer near me wanted $2100. I bought parts from ebay searching OE or OEM parts and bought at 1/2 price what my dealer charges…..exact same NIssan parts. I replaced the main tensioner, the guide and the main chain, both secondary guides and not the tensioners. Replaced both secondary chains. I found a mechanic on Craigslist near me who charged $400 labor. Parts cost me about $250. However, Service Engine Soon light still did not go out even after several drive cycles. My van would not pass Emission Inspection thus could not register with DMV. Culprit was the 2 Camshaft Sensors on Bay 1 and Bay 2 I replaced with Beck Arnley parts. Until I re replaced with Nissan sensors I had a catastrophe. Nissan sensors I replaced myself one night and immediately, took the SES light out and 1 drive cycle made Emissions Inspection turn to green light on my OBD II scanner. Next day I was the happiest man on earth.