I recently had my accentric shaft sensors replaced, ignition coil, tune up, and oil change and at the suggestion of my mechanic steam clean the engine, after a few days my car started surging when driving.
Youll need to make sure this is not a fuel problem. Hook up a fuel pressure gauge. Stick it by the wiper arms so u can see the gauge whyll driving. Drive and watch for a lose of pressure when it happens. Just rent a gauge from the parts store. Start here.