I think he is saying that nissan told him is the valve body? Not the throttle body. Two very different problems. If it is the valve body, they mean that in one side of your engine, the valves are not opening and closing correctly, making you lose power. I think a problem like this will give you an engine indication of some sort. With 140K your valve body should have no problems at all, unless one of the cam chain tensioners is lose and your valves are not synchronized. A few coils on one side dead at the same time could be doing the same. I had to change 2 coils on one side on my 2003 pathfinder which is basically the same engine and was showing those same signs of no power. If it is really your valve body, you should stop running the car right now and check your chain and tensioner, otherwise you risk catastrophic engine damage with bent valves or worse. If it is the throttle body a simple cleaning being careful, with the TB out of the car, and an idle relearn should fix the problem. Please let us know if you are talking about your mechanical valves or your throttle body.Q451990 wrote: ↑Thu Sep 28, 2017 8:27 amYeah, I can't imagine a failed <a rel="nofollow" href="http://rover.ebay.com/rover/13/0/19/Dea ... KU=3635581" target="_blank" title="Link added by VigLink" class="vglnk"><span>throttle </span><span>body</span></a> not tripping a check engine light. Did the dealer give you any reasoning behind their diagnosis? I can't remember... does the 04 coupe have one <a rel="nofollow" href="http://rover.ebay.com/rover/13/0/19/Dea ... KU=3635581" target="_blank" title="Link added by VigLink" class="vglnk"><span>throttle </span><span>body</span></a>, or two? I know the sedan went to a dual setup in '07, but I'm not sure on the coupe. Has anyone had the <a rel="nofollow" href="http://rover.ebay.com/rover/13/0/19/Dea ... KU=3635581" target="_blank" title="Link added by VigLink" class="vglnk"><span>throttle </span><span>body</span></a> off of the car? Manually opening it has been known to cause problems. There is a relearn procedure in the FSM (available at <a rel="nofollow" href="http://www.infinitiservicemanual.com" class="vglnk"><span>www</span><span>.</span><span>infinitiservicemanual</span><span>.</span><span>com</span></a> ) but in my experience you'd be throwing codes. Still might be worth a try.