2002 Dodge Neon

My Neon has started stalling when acclerating from stop. I can hear the engine backfire and then the engine goes back to having normal power. This stalling does not happen all the time. The spark plugs and ignition coil have been changed after inspection per repair manual. Have scanned the PCM several times and showing NO error codes. My scanner has capability to check sensors by driving vehicle; NO sensor errors even though vehicle went through stalling process, Have checked all vaccum hoses, fuel gas pressure is steady at 55psi at idle and continuous high rpm. Engine only stalls when driving, never in parked driveway. Any ideas or suggestions appreciated. Art Padilla