jerking when started and on low idle

Had diagnosed showed up 3 problems leaking oil,needs gasket, pluggs wires, and a sensor. replaced sensor, did pluggs and wires. would the oil leak cause the jerking? or is there something else wrong that will not show up when diagnosed?

Are you losing any engine coolant? I've had a few of these vans that did this and it turned out to be a head gasket. Each time it was losing antifreeze in cylinder #2.