code 12 is a problem with the EGR system 90% of the time it's not the valve but no vacuum going to the valve . so start by checking the valve then for vacuum frm the hose.jonED said:12 Blink code is your EGR valve....go to www.autozone.com/images/cds/gif/large/0900823d800cfb11.gif and this will tell all the codes