I have a 2005 Navigator with 95,000 miles. In February I had the timing chain replaced. Then in May I had solenoids, CV's, and phasers replaced. When coming to a stop I sometimes idle low and then stall out. I also can stall out when backing up from a stop. Occasionally I can get a hesitation when accelerating. I get error code P0012 Air Intake Sensor error messages. My mechanic gives up. Any suggestions?