OBD codes / P0171 / Ford Escape
P0171 on a Ford Escape
System Too Lean (Bank 1)
2.5L Duratec four, 1.6L/2.0L EcoBoost fours, and 3.0L Duratec V6 (bank 1).
What P0171 usually means on a Escape
P0171 means the engine, or bank 1 on the V6, is running lean and the PCM is adding fuel to keep up. On the Escape the usual causes are unmetered air from a vacuum or PCV leak, a dirty mass airflow sensor, and on the turbo EcoBoost engines a leak in the charge-air plumbing. On the 3.0L V6 an intake manifold gasket leak is a classic lean-code source as the engine ages. Symptoms range from nothing to a rough idle, hesitation, or reduced power.
Most likely causes on this model
- Vacuum or PCV leak
Cracked PCV hoses and intake gaskets let in unmetered air and are a leading lean-code cause on the Duratec engines, especially the aging 3.0L V6.
- Dirty or failing mass airflow sensor
A contaminated MAF under-reports airflow, so the PCM under-fuels and P0171 sets. Cleaning or replacing it is a common Escape fix.
- Charge-air leak (EcoBoost)
On the turbo engines a loose intercooler coupler or cracked charge pipe leaks metered air after the sensor, driving fuel trims lean under boost.
- Weak fuel delivery
A tired pump, clogged filter, or dirty injectors can starve the engine enough to log a lean code, particularly under load.
What it costs on a Escape
Most P0171 fixes on the Escape are inexpensive: cleaning the MAF, replacing a PCV hose, or reseating a charge-pipe clamp. A smoke test is a small diagnostic cost that pinpoints leaks and prevents parts-swapping. It only gets costly if fuel-pump or injector work is needed, so confirm the cheap items first.
Fixing it
Read fuel-trim data and smoke-test the intake, plus the charge pipes on an EcoBoost, before buying parts. Clean or replace the MAF and cure vacuum/PCV leaks first, since those are the usual causes on this vehicle.
For the full step-by-step diagnosis order (any vehicle), see the main P0171 guide.
Year, engine and mileage change the answer. Get a diagnosis for your Escape — it weighs these causes against your exact configuration and real complaint data.
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Based on widely reported patterns for this model; individual causes vary by year, engine and history. Generic P0171 behavior is covered on the main P0171 page. Confirm with a scan tool before buying parts.