[geoii98]

I have a automatic transmission in this car. It has high mileage but runs pretty good. However, occasionally the car starts to idle up and down and when I let off the gas while driving sometimes gets real jerky and then smooths out by itself or when I give it gas. When I come to a stop sometimes it idles up and down and then cuts off. I have found that if I unplug the battery for a few minutes the problem goes away for the biggest majority of the day but eventually starts happening again. I have changed the plugs, wires, and distributor cap. I even tried a new idle/air control valve and throttle position sensor and got nothing different. I have also put a new fuel filter on it with no results. I am thinking possible vacuum problem. It also has a real rich exhaust smell while running. I have gotten the codes of 25 and 26 which is too rich and too lean. I replaced the oxygen sensors as well with no results. The car runs great so long as my foot is on the gas. ANY IDEAS?