It passed the safety inspection with no problems, but the mechanics are stumped on why only 3 of the 5 tests are "showing up" for the Missouri emission test. Two of the tests consistenly won't even register so they don't know what to suggest to fix it. Other than driving it more.......any ideas.
Won't pass Mo emissions test, mechanics are stumped on 2004 Hyundai Sonata
by not a car person in Saint Louis, MO on November 09, 2012
ANSWER by ziptie12 , November 12, 2012
Are you referring to 'readiness codes'?? Bring to Hyundai to verify proper function of OBDII system.
ANSWER by your.mechanic , November 11, 2012
have competent technician check it