has anyone had problems with there cobalt bucking. I have a 2010 LT with manual transmission 50000 miles on it now. I bought it brand new and I have car serviced regularly. sometimes when I am driving the car starts to buck and it could be in any gear at any speed. no codes are being displayed. I replaced fuel filter and spark plugs so far. it doesn't happen very often out of the blue it will do this and sometimes when I turn on ac.