Did you or did you not have to pay anything in the end? If you did contact the Chevy Customer Care staff here on CruzeTalk. Over 90% of the P0171 problems have been the valve cover which is a powertrain item. You're one of the few who has had the MAF sensor replaced and I don't know if it's covered. If you're still experiencing the repeated bumps every 3-5 seconds while stopped this is an internal transmission issue that is also covered under the powertrain and the dealership didn't bother to replace the components per the TSB that Robby mentioned.I got a call back yesterday about my car from the dealer as I did leave it with them and got a loaner. They did end up looking it over again. I did leave with it and turned back around after paying a 85.00 diagnostic fee and them telling me I needed a fuel system flush for 300.00 to fix the 2 codes had me a little pissed. They ended up replacing the MAF and Valve cover and said it was ready. They also said this would take care of the trans issue of the bumping ahead when at a stop. Fingers crossed.