Shaggee

Having a problem with a High idle problem in my 2000 OB Manual. Idles high at about 900 - 1000 rpms. took it to the shop. Air/Fuel sensor was not responding at all so mechanic changed that sensor. Was good for about 2 weeks. second time around I tried unplugging the battery hoping it would possibly reset the computer. Seemed to help temporarily. Now it's in and out. Will drive fine for a while then go into high idle. fluctuates up and down a little. 2 weeks ago it happened right after the local temperatures heated up. second time happened after temperatures cooled down (coincidence?). Originally after I bought this vehicle it was jolting as I was driving. It would actually deaccelerate. When I pushed the throttle, it would take quite abit of pressure to get it going again. The dealership replaced throttle position sensor and the neutral switch when I orginally had the problem after purchasing vehicle. The neutral switch fixed it for about a year until the winter set in again, which is when I purchased the vehicle. The only thing that was done last winte was resetting the computer, which fixed it until 2 weeks ago. The recent problem started with these symptoms, but not as extreme. Please Help!!! REALLY TIRED OF THIS PROBLEM. Thank You