My car has been serviced three times with the first repair for code P0401 where all my EGR sensors were changed, engine light stayed out 1 day, light appeared back on ,had it checked code P0174 shows up with code P0401 mechanic checked it again said he had to clean vacuum hoses, ok engine light out for 1 day appears back on on 2nd day ,i also failed inspection iam ready to throw in the towel i have 30 days to have repairs done before re-inspection ,what should i do next please help the car also has a burn smell .
i have 2 obd codes of PO174, and PO401 i had my car repaired twice on 1999 Mercury Sable
by rescue099 in Newark, NJ on April 25, 2012
ANSWER by globalhelper on April 25, 2012
po174 is system lean bank 2 and po401 is egr insuff flow. the 1st code needs to have a smoke test to find possible vaccum leak and the other is possibly the dpfe valve or hoses going to it are disconnected or broken