Volvo S70 Stalls at Lights, now while driving

What is wrong with my 1998 Volvo S70 with 135,000 miles. It stalls at lights and now hesitates also while driving and even stalled once while driving. Dealer says it is the fuel pump failing or the air mass meter but I don’t want to start throwing money at it. It did seem to start after we bought a new battery.