1995 Plymouth Voyager engine light

I have replaced the oil, filter, plugs, distrubter cap, wires, air filter and cleaned out the throttle body with a cleaner. After about 20 mins or so of driving and the tempeture rises up the engine light comes on. It also feels like it shimmmies like a bad wheel. Sometimes it wants to stall and then it gets gas and reeves up. I am not sure what the problem is and at wits end. I also tried looking for the pcv valve but cant seem to locate it. It idles and starts no problem. It doesnt shake or bang but it does seem to rev up n down when idleing. Any and all help will be great thnx.