2.7 engine stalling / rough idle

Hello.
I have had an ongoing intermittent problem with my 2.7 engine. It will stall or idle rough without an apparent pattern. It may be cold or warm, dry or raining. The dealership has had the car 3 times. Once they replaced the TPS(throttle position sensor), cleaned the fuel system/injector and "reset" the computer. It wil run fine for days and then try to stall or idle erratically. Even on the highway it will suddenly feel like its missing or running out of gas but only for few seconds. The dealer is stumped and so am I. BTW The dealer claims to have checked the fuel pressure as well. HELP !

how long has it been since you had a battery put in your car?

Have to admit the battery wasn't something I had considered. It happened again today I was driving between Guelph and London, about 1.5 hours, and it started acting up again. It really "feels" like a fuel problem. I was at a stop light and the engine tried to "surge" before the rpm's dropped and almost stalled. Then when I'd been on the highway a half hour and doing 120 k (about 75 mph) and the engine felt like it was "missing" or "stumbling" and it only last a couple seconds. No check engine light and I really wish I could find a pattern to this. I'll get my battery load checked and see how it is, its the original. I think I heard something about problems when some of the cells or plates go bad.
Thanks.

If your car is a 2002 or prior, and you still have the original battery, it's time for a new one. I had to do the same thing on my 2002 Intrepid. Battery's don't last long because there are so many more electrical accessories on the car that drain it in 3 years or less.

Ever come up with a fix on this? My daughter has the same problem. A weird thing I noticed is that if you turn on the headlights the idle smooths out. Probably a coincidence, but always works regardless of how long I wait to try it.