Early 06 optima 4 cyl. Code po420 cat. Below eff. Threshold bank 1
replaced both coil packs a couple months ago due to misfiring, could this have damaged the cat. Converter or rear O2 sensor. Neither one are cheap and trying not to guess too much. Local shop checked evap system and found no problems. Of course won't pass inspection now.
any insite appreciated
Monday, February 4th, 2013 AT 10:28 PM