'96 Grand Cherokee Problem

My '96 Grand Cherokee Limited started doing something strange recently. First of all, I noticed that the fuel economy isn't as good as it used to be. Going 60 mph on straight flat highway gives anywhere from 16-20 mpg and the engine is about 2,000 rpm. Is this about right?

However, yesterday I picked the vehicle up from our body shop as a dent was getting repaired. After starting it, it would stall out pretty quickly when idling. It idles low at about 500 rpm. Fast idle is 1,000 - 1,100 rpm. It's been fine since but it did it more than several times then.

Also, when applying gas now, I noticed that the rpms don't go up smoothly, they rather jump. The needle moves just fine, but not as smoothly as I remember. When going 60 mph, if I take my foot off of the gas, the rpm meter drops immediately from 2,000 rpm to 1,000 then jumps back up. Any ideas if there is something to worry about here??

Thanks!

Maybe the body shop broke a wire or cut it by accident while fixing your car and it could be touching ground, have your computer checked by a diagnostic machine at the mechanic.

I would suspect the distributer cap and rotor.
Especially if it is over 100,000 mile on the Original one.

replace the o2 sensors.
gas mileage is effected radically with worn sensors. thats that problem,