I have a 91 Ford Explorer and the other day I was coming home, and on the highway the transmission was shifting from OD to drive back and forth, then the check engine light went on? Id get to a small town and the check engine light would go off and it seemed to run fine. Then when I got back up to 60mph it started doing it again. When I got home the Idle speed in park was about 2000 RPM. Is there a sensor or something that would cause this to happen?? Any help will be greatly appricated.

I am a college student and dont have alot of money so any info will help alot.
Thanks

 

Yoda, you first need to retrieve the CEL code. It's easy to do with an OBD I system which you have. Do a search and you'll get lots of info on how to do it with just a paper clip. After you get the code, we can give you more suggestions.....

 

Procedure and code are on www.batauto.com in tech or trouble codes. I imagine you have a big vacuum leak. look at the vacuum tree at the drivers side of the intake manifold. It has been reported some of these caps fall off.

 

I dont think its a vacume leak because now when I drive it now, it appears to be fine. It sounds like maybe some lever or something must be stuck to make it work fine and than not work fine. As to finding the code I have no idea how to do that or where to look for it at the website you listed. I do thank you for your help. But I dont understand the code thing.

 

Try www.dalidesign.com/hbook/eectest.html I couldn't find it at batauto.com even though I know it was there at one point.