Acceleration problems ,at hiway speeds, needing more speed car downshifts sputters misses then eventually snaps backto normal whats up?

Ok. I'll give you my best guess, although I am not a Dodge Stratus expert. Based upon your description of the problem, I am to assume that the vehicle has problems accelerating up to speed, but once there, cruises ok unless you are going uphill or need to accelerate quickly, then power falls off rapidly and acceleration returns very slowly. If that is accurate, I would suspect the EGR valve. This is because at ihighway cruising speeds the EGR valve is pretty much wide open, letting exhaust gases back into the intake. When you need to accelerate, pressing the accelerator results in intake vacuum drop. This is partially compensated for by closing the EGR valve. If the EGR fails to close or sticks partway open, the exhaust gases will lower intake vacuum even further, and rob engine power. This can also cause the onboard computer to force a downshift to the transmission, as vacuum sensors are used to determine engine loading and the need to reduce gearing. In addition, a partially open EGR valve can cause erratic idle as it affects static intake vacuum (EGR is normally closed at idle) and the onboard computer must continually compensate, resulting is unstable idling.