I purchased this car with 460 miles on it and found it was one of the cars with the possible engine piston issue that GM released a TSB for. at check nothing was noted out of the ordinary. The car takes longer to crank before it starts than I am used to . Also today at a stoplight the engine clearly missed as the RPM dropped about 200 rpms and quickly rebounded. the car runs premium fuel and 5w20 Mobil one oil. Acceleration is fine and the engine is quiet from what I can tell. While none of these issues is major because of the potential engine issue they concern me. Anyone with this car or engine experience anything out of the ordinary? Thanks