Thinking about buying a 2004 Tiburon from a dealership. Its clear and everything but on the carfax report its been thru 5 emission tests and has failed. The dealership has told us that since the battery was out for a bit it reset the comp and that the car has to be driven for 90miles or so for it to complete the drive cycle and everything and start clearing with the emission test. Any advice? is this accurate? and what could it be that is causing the car to fail the test?