The Lemon IndexBank 1 is getting too much air or too little fuel.
Get it fixed soon. A few more days of normal driving is usually OK, but waiting can turn a small repair into a bigger one or a breakdown.
Vacuum leak (hoses, intake gasket, PCV). Then: dirty MAF sensor; weak fuel pump or clogged filter.
Owners named P0171 in 154 complaints to the U.S. government, most often on the Ford Windstar.
Models that report it most
Complaints that name P0171, by model. Raw counts, not a failure rate: popular models get more complaints. Tap a model for its years, mileage and what owners say fixed it.
P0171 by model: P0171 Ford Windstar (18) · P0171 Chevrolet Cruze (10)
Years owners report it on most: 2001 Ford Windstar · 2000 Ford Windstar · 2002 Ford Windstar · 2013 Chevrolet Sonic · 2003 Ford Windstar · 2012 Chevrolet Cruze
The details
What P0171 means
Bank 1 is getting too much air or too little fuel. The engine may hesitate or idle rough.
Can I drive with P0171?
Get it fixed soon. A few more days of normal driving is usually OK, but waiting can turn a small repair into a bigger one or a breakdown.
27% of the owner complaints that name P0171 also say the car stalls or shuts off. A complaint can describe more than one problem, so this doesn't prove the code caused it.
Common causes of P0171
- Vacuum leak (hoses, intake gasket, PCV)
- Dirty MAF sensor
- Weak fuel pump or clogged filter
- Leaking exhaust before the O2 sensor
A shop should confirm the cause with a scan and tests before replacing parts.
What owners describe
- Stalls or shuts off: 27% of complaints
- Shakes, runs rough or misfires: 20% of complaints
- Loses power or goes into limp mode: 18% of complaints
- Brakes or ABS act up: 14% of complaints
Share of complaints naming the code whose text also mentions each problem.
Model years that report P0171 most
2001 Ford Windstar (6), 2000 Ford Windstar (5), 2002 Ford Windstar (4), 2013 Chevrolet Sonic (4), 2003 Ford Windstar (3), 2012 Chevrolet Cruze (3).
Related codes
P0170 P0172 P0174 P0175 P0190 P0191 P0192 P0193
Quick answers
What does P0171 mean?
System Too Lean (Bank 1). Bank 1 is getting too much air or too little fuel. The engine may hesitate or idle rough.
Can I drive with P0171?
Get it fixed soon. A few more days of normal driving is usually OK, but waiting can turn a small repair into a bigger one or a breakdown.
What causes P0171?
Vacuum leak (hoses, intake gasket, PCV); Dirty MAF sensor; Weak fuel pump or clogged filter; Leaking exhaust before the O2 sensor.
Counts: NHTSA owner complaints whose text names P0171. A complaint is an owner's report, not a diagnosis. Meanings: the standard SAE J2012 definitions in our own words; manufacturer codes only where verified for that make. General information, not repair advice for your car.