Check loose hose clamps for rubber hoses and check for broken or cracked hose lines too. Do you, by any chance, have a leaky exhaust in the front?

From TSB.
P0174 - System Too Lean (Bank 2-Radiator 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


"Always do the cheap and easy ones first." 1996 V6 ATX 96K miles