Those Pesky Lean-Condition Codes
This particular vehicle gave us two codes: P0171 and P0174. It is important to note that neither of the codes was current; they appeared only under “Memory Codes.” In a situation like this, I look at freeze-frame data, and we had the following data snapshot from when the code set: vehicle speed, 38 mph; coolant temperature, 189°F; long-term fuel trim for both engine banks was at 14% and 17%; engine speed, 1,803 rpm (Figure 2).
