I have a 2005 Dakota v8 for some reason the gas guage will go down to empty then slowly work back up to full or where ever its supposed to be according of how much gas I have in it then it will drop again sometimes staying there and the check engine light will come on and stay on. does not affect how the truck runs which is great. ive put a new battery in it alternator is charging good checked every connection on truck fuses are good.got any ideas

 

What is the code from the check engine light? Can't help you until you post the code. The truck is literally telling you what's wrong.