I went out to my baby this morning and started her up, then my problem started (my car is Automatic). When in Park or Neutral it jumps up from about 1,800 rpms to 3,000 rpms then back down and back up, and will continue to do that. When in D4 it idels at 2,000 rpm's when it should be at about 1,000 rpm's. And finally when traveling in speeds of 30-45 mph and foot off the gas the needle on the tach will go from about 2,000 rpms and then drop to about 1,700 rpm's and continue doing this until I step on the gas or slow down substancially; the car also does a noticable lungeing front to back like ur on a rollercoaster going up to the top. I disconnected my battery to reset the ECU and that didnt work. I need help.

 

sounds like the tranny is starting to go

 

How many miles do you have on her?

 

She has about 70,350 miles.

 

Check the TP (throttle position) sensor.

 

It was the Map Sensor