2011 MERCEDES-BENZ SPRINTER 2500 Engine Problems

I HAVE AN RV BUILT ON A MERCEDES DIESEL CHASSIS. ON JULY 3 MY CHECK ENGINE LIGHT CAME ON I TOOK IT TO MERCEDES OF TAMPA FL. THEY SAID THAT IN WAS THE OXYGEN SENSOR, BUT DID NOT HAVE IT IN STOCK NOR WAS THERE ONE AVAILABLE AT ANY OF MERCEDES WAREHOUSES IN THE US. IT WOULD HAVE TO COME FROM GERMANY AND IT MIGHT TAKE MONTHS. THEY RESET THE LIGHT AND TOLD BE I COULD TAKE IT BACK TO MD WERE I LIVE AND HAVE THE LOCAL MERCEDES FIX IT. THEY ASSURED ME THAT IT WOULD NOT HARM THE ENGINE AND I COULD DRIVE IT BACK. ABOUT 200 MILES INTO MY RETURN TRIP ON JULY 5TH (EXIT 29 IN GA), I STARTED TO LOSE POWER AND COULD ONLY GO BETWEEN 30 AND 40 MPH ON I 95. I FINALLY CAME TO AN EXIT AND PULL TO A TA TRUCK...

[XXX] IS CAR WASH STORE? IN MARCH 21, 2013, VEHICLE WARNING LAMP CAME ON AGAIN, THE INFORMATION IS :"ENGINE OIL LEVEL NOT WHEN ENG RUNNING", ON THIS DAY I ONCE PUT MY CAR TO THE [XXX], IN MARCH 26, 2013, [XXX] SEND THE CAR BACK, THEY TELL US, THE VEHICLE IS NO PROBLEM. I CHECK THE VEHICLE FOUND, "ENGINE OIL LEVEL NOT WHEN ENG RUNNING"WARNING LAMP STILL ON . I DON'T KNOW WHAT'S PROBLEM ON THIS CAR? I DON'T KNOW IF I USE THIS CAR IS BE SAFE? I WANT THIS CAR TO THE GOVERNMENT SAFETY SUPERVISION DEPARTMENT TO DO THE IDENTIFICATION, TO CONFIRM THAT THE CAR IS IT RIGHT? SAFETY? INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6). *TR