Check engine light code 174 lean bank 2. Was told it was intake plenum gasket on 2004 Ford Taurus

Have a check engine code 174 engine lean in bank 2. was told to replace intake plenum gasket. I did, and throttle positioning sensor,imur gasket, idle control valve cleaned, mas airflow sensor cleaned. Why do I still have this code. Could it be a bad o2 sensor? Oh I also checked all vacuum lines for leaks.

by in Jamestown, NY on January 06, 2013
1 answer 3 comments
ANSWER by , January 06, 2013
More than one engine was used in these cars you know which one you have??
COMMENT by , January 06, 2013
I have a v6 OHC Engine with 131,000 miles on it.
COMMENT by , January 06, 2013
3.0 DOHC V6. Did you replace the INTAKE gaskets? If not that may be the problem. Could have it tested. Good luck with it.
COMMENT by , January 06, 2013
OHV V6 I replaced the upper plenum gasket because the engine was running pretty rough at idle and I was getting the code so I was told to replace the upper intake plenum gasket so I did. I even replace the runner control gasket, cleaned mas airflow sensor, cleaned ide air control valve, and checked for vacuum leaks on all hoses and never found any leaks. Since I replaced the upper plenum gasket the car does run alot smoother but the code came back. When I say came back, I disconnected the battery to remove the plenum since I had to unplug all the electrical components that were connected to the upper plenum.