Ford Mondeo keeeps stalling

number one injector went and the this cylinder was above knock limit so i took it too garage!reprogrammed all but number 2 injector as code missing!all quiet and running as was but she started stalling when you came down the gears to slow down or stop.noticed only that mpg better.64? but in reality it was the normal 50mpg!so back to garage and injectors changed with fuel filter.sill stalling.cam sensor changed.better but still doing it and its dangerous as you go around a corner.also if you rev her to 3000 revs then take your foot off accelerator she will stall