Car dying when you let up off the gas

Have you checked for codes yet in the computer? Also the fuel filter gets changed every 100,000miles.

The check engine light isn't on and it doesn't have any codes.

I would see if the coolant temp sensor is good you would read thetemp on the scan tool and compare that to the actual coolant temp using a infared temp gun.Also is there a lack of power while driving?

It's actually a 2004 but that doesn't matter that . Anyway we took it to a friend and he checked out the coil pack and it was good. He thinks it's either water in the gas tank or stopped up fuel injector. It has power when you give it the gas but when it's idling it will either die or putt putt around and act like it's going to die. We changed the fuel filter yesterday also. The engine light isn't on or we would've already had it hooked up to a machine. We were told to put some sea foam stuff that suppose to get water out of the gas tank in it and are driving up back and forth in front of our house in case in breaks down. Thanks for the help and if you can think of anything else let me know.

I forgot to add that when it's in gear in a stopped position it putt putts, tries to die if it don't die and the most important thing is it jumps like. Feels like it's trying to take off or motor feels like it's jumping. No motor mounts aren't broken or anything like that it just feels jumpy.