It has 152,000 miles on it. I've replaced upper and lower intake manifold gaskets, crankshaft position sensor, Ignition control module, thermostat, temp sensor, plugs, wires, oil and filter, trans filter and fluid, and the fuel filter. Car runs great. Smooth, starts right up. I can drive it or just let it sit and Idle. Lets say I just let it sit and idle, after 30 minutes it will rev up then back down and stall. Will start right back up but then do the same thing in a minute or so. What is making it do this. Should I replace the cam position sensor or is that not it? There is no check engine light that comes on, unless it is burnt out. Guess it could be. Could there be a vacuum leak? I am lost at this point. It runs the best it has in a long time but wants to stall at a red light or just idling after, about 30 minutes. It does not leak a drop of anything on the ground. Before I replaced the intake manifold gaskets it leaked all the time. Please help. I am gonna drive it and have it scanned to see if there are any codes. Any help or suggestions would be great. I am stuck.