I have a 2003 Jeep Liberty Limited Editon. I've had it for 6 years now and it's been nothing but good to me! I bought it used and it now has 214,000 miles.

In June 2014 I was having trouble starting it. I replaced the battery since it was 5 years old and needed replacing. However it ended up being the camshaft sensor. Since then my Jeep has run perfectly fine! Until Tuesday (November 2014) I was leaving work and my battery light came on. It's a 30 minute drive for me to get to my nearest auto parts store so the next day I started to make my way up there. About 5 minutes into my drive the radio completely shuts off, won't show the time or anything (which I knew was a sign of a dead/dying battery) I start to come into town and I'm at a stop light when my air bag light comes on. I thought that was weird but again maybe that's just because the battery is bad. The light turns green and my car acts like it doesn't want to go and I notice that even though I'm moving and my RPM's are going up my speedometer is still on zero.

I come to another stop light where I need to turn and notice it's very difficult to turn the steering wheel. I then come to another stoplight where I have to turn and it's still very difficult, then all the sudden my car gets some kind of surge of energy and zooms forward almost causing me to rear end the car in front of me, at the same time the radio comes back on, the air bag light shuts off and the speedometer goes all the way up then back down to zero then moves to the speed I am actually driving (at least I think). I finally get to Advanced Auto Parts and they check the battery and say it's no good. Seeing as I got the battery at Walmart in June I drive to Walmart. When Walmart checked everything they say the battery and alternator and starter are fine. I'm frustrated but not much I can do about it so I go on about my day.

After Walmart checked the battery the battery light is off for a period of time but then comes back on. Now it's Thursday and I've taken the Jeep to a local guy who just works on the electrical aspect of the car, he has it for the whole day and cannot find anything wrong. He's tested multiple things and and finds nothing wrong with it. I don't know where to go from here. I'm scared to drive the vehicle any significant distance for fear that it will start messing up like it did before or lurch forward causing me to be in a wreck.

I also noticed that my average mileage per gallon (gas) has been fluctuating significantly since this began I usually get between 16 and 20 MPG but when I glanced up it was only at 10.3. I kept an eye on it and when I would accelerate, the AVG. MPG would go down significantly. It went from a 10.3 to a 7.8 in less than a minute. When I would approach a red light and coast/apply brakes, the AVG. MPG would rise significantly, from the 7.8 to 14.9, then go back down once the light turned green and I accelerated. Also when all of this was happening the gas gauge was physically moving when I would coast/apply brakes and MPG would rise the gauge would be at half a tank. When I started accelerating the gauge would go down to 1/4-1/8 tank. I'm just looking for things to have mechanics test for. Anyone I've talked to looks like a deer in headlights when I tell them everything that's going on and say they've never heard of anything like this. Please help!