Check engine

[contourdude]

I did the check because the Check Engine light popped on and hers what i got

P0402 EGR Flow Excessive
P0420 Cat efficiancy below threshold
p1131 manufacturor control fuel air metering
P0171 System too lean
P0174 System too lean

So i made an appt at the local shop, but what is wrong w/ my car? Its got 34,000 miles.... Is it prolly an 02 sensor.. What do you think this will run me? Thanks

[Tony2005]

1) Check for vacuum leaks (broken hose, gaskets, etc.). If necessary, spray carb cleaner and if the idle changes, you found your leak.

2) Clean throttle body.

3) Then reset computer. Pull Fuses 4 and 11.

4) If CEL appears again, scan and post new code(s).

Edit. TB Cleaning
http://www.contour.org/ubbthreads/showflat.php?Cat=&Board=trouble&Number=920243&Forum=trouble&Words=p0401&Match=Entire%20Phrase&Searchpage=0&Limit=25&Old=allposts&Main=919728&Search=true#Post920243

[BrApple]

excessive egr flow at idle is most likely the dpfe sensor ...

[Tony2005]

excessive egr flow at idle is most likely the dpfe sensor ...

DPFE how to in Autozone link
http://www.autozone.com/servlet/UiBroker?ForwardPage=/az/cds/en_us/0900823d/80/1b/ca/1e/0900823d801bca1e.jsp

[BrApple]

also thinking about it clean the maf and I bet that the lean codes will go away if the maf is infact dirty and not reading correctly ...