2004 chrysler sebring in the AM starts well, drives well for approx 15 mins then starts to jump. Is it the Fuel pump or filter or both?

yes. In the AM ambient conditions are cool and your ECM wants to make the mix rich....by afternoon, the ambient air temperature sensor has not come to duty yet...so replace your ambient air temperature sensor...will see if I can tag one for you~

I am 99 2/3% sure this is our failure~

dag...five dollars and fifty four cents....Cocktails or an airport coffee is more than that....have some faith in the judge~there is a device called the fuel pressure regulator that keeps everything on the groove~ erratic pressure=vacuum leak at it's diaphragm...is another thing...

Will try the sensor replacement..can you say where it's located on the 2004 2.4 DOHC 4 door SEDAN Sebring (not convertible).?

go to rockauto.com and order the correct one~

Where is fuel pressure regulator on a 2004 Chrysler convertible