2011 Volkswagen Passat Fuel System Problems

AN EMAIL I SENT TO DARCARS/ SILVER SPRING: IN JUNE OF 2016, I NOTICED MY CAR "PUTTERING" AND ALMOST STALLING OUT. A FEW DAYS LATER, MY ENGINE LIGHT COMES ON. I IMMEDIATELY CHECK THE OIL LEVEL, WHICH WERE GOOD. I THEN BELIEVE THERE TO BE AN ISSUE WITH THE MUFFLER, OR MANIFOLD. IN JUNE OF 2016, I BROUGHT MY CAR IN TO DARCARS DUE TO THE ENGINE LIGHT BEING ON. WITHIN A COUPLE HOURS, I WAS TOLD THERE WAS AN ISSUE WITH A VALVE (UNCLEAR INFORMATION PROVIDED BY THE RECEPTIONIST) UNDER THE HOOD. THE ACTION PROVIDED WAS UNDER WARRANTY, SO I HAD TO PAY NOTHING. I GOT MY CAR BACK THE SAME DAY...ENGINE LIGHT OFF, AND I DROVE HOME A FEW DAYS/WEEKS LATER, THE ENGINE LIGHT CAME BACK ON. I RETURNED TO DARCARS, AND TOLD THEM THE LIGHT WAS ON AGAIN. THIS WAS AROUND AUGUST 2016. THE RECEPTIONIST, TOOK THE CAR IN, AND PROVIDED A LONER CAR. A FEW HOURS LATER, I WAS TOLD THE ACTION REQUIRED WAS UNDER WARRANTY, AND THEY WERE FIXING IT. AGAIN, THE RECEPTIONIST MENTIONED A "VALVE" REPLACEMENT. (VERY UNCLEAR COMMUNICATION) I DROVE THE CAR A FEW MORE DAYS, THE ENGINE LIGHT CAME BACK ON...I BROUGHT IT IN...I'M TOLD THE EXACT SAME INFO AS BEFORE. EXCEPT FOR NOW, I'M TOLD DARCARS HAS TO "SEND-OFF FOR A PART" . I'M PROVIDED A LONER, AND IN A FEW DAYS, I GET MY CAR BACK. THE ENGINE LIGHT IS OFF. THIS IS IN SEPTEMBER OF 2016 SAME STORY... ENGINE LIGHT COMES BACK ON(OCTOBER 2016), AGAIN, THE ENGINE LIGHT RETURNS, ALONG WITH THE LOW TIRE PRESSURE LIGHT. I BRING IT IN ON A WEDNESDAY (BEFORE THANKSGIVING). I INFORM THEM OF THE ISSUE. THE RECEPTIONIST ASKS ME CAN I LEAVE IT. I INFORM HIM I'M GOING TO SOUTH CAROLINA FOR THE HOLIDAY AND WOULD RETURN THE DAY AFTER THANKSGIVING. I ALSO HAD SOME ERRANDS TO RUN THAT DAY (WEDNESDAY), COULD I HAVE A LONER. HE TOLD ME "NO", "YOU'LL BE FINE IF THE ENGINE LIGHT IS ON. JUST AS LONG AS IT'S NOT BLINKING". *TR