I cant remember what I had replaced about 5-6

I cant remember what I had replaced about 5-6 months ago, seems like it was a sensor. My 1993 Ford Explorer is not running or idling at normal speed. When I pull up to stop it is like it stays engaged and wont idle down. Then when I 1st start it it wont stay running at all. If I have to be stopped at traffic lights for any amount of time I have to put it in neutral and keep the engine idled up high. Seems like it was the map sensor but then again its almost like it was oxygen sensor.