ESP BAS lights on, no cruise and now engine bucks

Hello--dealer did this: tune up --changed plugs and pressure cleaned fuel rails to remove carbon. The car is eligible for the free fuel tank and fuel pump and check valve sensor assys. This is due to stalling and rough running and is the X53 issue for this car. This they had to order. They put plug wires on wrong--crossed 7 and 1, the service guy acknowledge the error after I brought it back--later he would admit to nothing except the mech" made a adjustment". Car still stalls and bucks occasionally. The lights for check engine BAS and ESP are off. I will take car back for the fuel tank and associated pump and sensor replacements--after 4th of July. I pray that fixes the car. The dealer has a better diagnostic device--but they still did nothing except plugs and the pressure clean of fuel rail and throttle body --at $467 and change. I truly pray the fuel tank and assy fixes all the problems so I can sell the car, and buy a new vehicle.

Hello! Yesterday I dropped off 300C at dealership to replace fuel tank. I was told by dealer that tank is only thing relaced on X53 issue-they redesigned tank so fuel doesnt end up in EGR --thats what service manager told me. On way there my car stalled again with only 1/4 tank--i restarted in neutral and car moved around corner and seemed to stall again. I pulled quickly off road and put car in neutral and it was surging low rpm and Electonic Throttle Control light appeared. I shut car of 10 minutes--restarted and drove safely to dealer without further issue. I pray the tank fixes all. I hate going to a dealer--except for warranty work.

Hello---I had the fuel tank replaced last week. Yesterday car stalled 3 times on me---no lights on dash. I am taking car Wednesday to a reputable local garage to have front brakes done(rotors and pads) and a wheel bearing replaced--maybe. I want to tell them to have a Crankshaft positioning Sensor on hand to replace--This has shown up on 90% of all scans of the codes. I understand it can cause stalling and rough idling--Also APPS under gas petal can too, or electronic module. I want to sell this car asap---but want to solve stalling 1st for obvious reasons. I DONT want to just start replacing costly parts. What is your best opinion on cause of stalling for this car please? Thank you very much!