iv just had my 2012 worked on where the cam shaft sensors were replaced because thats what the "diagnostics" said was the problem; the car was jerking on accleration at times before like it was going to cut off......they tested it and i did to before driving it off. now that i get down the road a little ways... going at about 35 40mph i start to feel the jerking again.... it is also after some stop and go at a light... the mechanic said they can take a look at it again BUT good grief..what would cause it to do it again even after tey said they tested it on the road...me to in the parking lot next door....?? i was orginally told it was spark plugs, twice,,,then this mechanic said the spark plugs look ok and a diagnostic would tell them exactly..so it was the sensors.....SO WHY AFTER REPLACING THEM DOES IT SEEM TO BE DOING IT AGAIN?? who has any advice on this?? im about ready to go througj a mechanic course myself....paid almost 600$ to have this done....who should i trust..? first two mechanics? diagnostics? this mechanic?PLEASSE ADVISE?