Originally posted by ConnContour:
.... Went to AutoZone and had P0171 and P0174 come up. Car idles nicely since I tightened down the EGR bolt. Car idles rough for a moment when it is warm just after I start it. I had the O2 sensors replaced 73000 miles ago. Also the car pings at just about any speed with medium throttle.
Suggestions??? 
I don't think the O2 sensors are the issue. Check for vacuum leaks, clean MAF and put in a bottle of gas stabilizer.
From TSB.
P0171 - System Too Lean (Bank 1 Firewall side) The Adaptive Fuel Strategy continuously monitors fuel delivery hardware. The code is set when the adaptive fuel tables reach a rich calibrated limit.
Fuel System:
�· Contaminated fuel injectors
�· Low fuel pressure or running out of fuel (fuel pump, filter, fuel supply line restrictions)
�· Vapor recovery system (VMV)
Induction System:
�· MAF contamination
�· Air leaks between the MAF and throttle body
�· Vacuum leaks
�· PCV system concern
�· Improperly seated engine oil dipstick
EGR System:
�· Leaking gasket
�· Stuck EGR valve
�· Leaking diaphragm or EVR
Base Engine:
�· Exhaust leaks before or near the HO2S
�· Secondary air concern
Powertrain Control System:
�· PCM concern
P0174 - System Too Lean (Bank 2 Radiator side) Same as DTC P0171, but Bank 2. See Possible Causes for DTC P0171
Edit. Duratec Maintenance for MAF cleaning.
http://www.contour.org/ubbthreads/showflat.php?Cat=&Board=v6maint&Number=958650&page=0&view=collapsed&sb=5&o=7&fpart=1
Last edited by Tony2005; 10/12/05 12:57 AM.
