Honda CR-V P0171
TL;DR
P0171 on the CR-V signals a lean Bank 1 mixture, most often from a vacuum or PCV leak, a dirty MAF sensor, or a weak fuel supply. Diagnose soon; caution while driving.
Why P0171 shows up on the Honda CR-V
The CR-V uses a mass air flow (MAF) sensor to measure incoming air, and the ECM trims fuel to match. When the real air-fuel ratio drifts lean on Bank 1, fuel trims climb and P0171 sets. On this model the fault is very commonly an unmetered air leak — air entering after the MAF that the ECM never accounted for. Older, higher-mileage CR-Vs are especially prone to hardened PCV hoses and intake boots that crack with heat cycling.
Model-typical causes and rough likelihood
- Vacuum / PCV hose leaks (~35%) — cracked, brittle, or disconnected hoses are the single most reported cause on the CR-V.
- Dirty or aging MAF sensor (~25%) — a contaminated sensor under-reports airflow, so the ECM adds too little fuel.
- Torn intake boot or loose clamp (~15%) — the rubber duct between MAF and throttle body splits over time.
- Weak fuel delivery (~15%) — clogged injectors, a tired fuel pump, or a restricted filter starving the engine.
- Intake or exhaust manifold gasket leak (~10%) — less common but possible on high-mileage units.
Owner tips
Before spending money, inspect and reseat every vacuum and PCV hose, and check the intake boot clamps. Cleaning the MAF sensor with dedicated MAF cleaner (never brake cleaner) fixes many cases cheaply. If lean trims persist after those checks, have fuel pressure and injector performance measured. Avoid long high-load drives with an active lean code, since sustained lean combustion runs hot.
Summary
| Code | P0171 |
|---|---|
| Meaning | System Too Lean (Bank 1) — too much air or too little fuel |
| Severity | Medium |
| Can I drive? | With caution — diagnose soon, avoid heavy loads |
| Most common cause | Vacuum/PCV hose leak or dirty MAF sensor |
| Typical repair cost | $50–$350 (leak or MAF); up to $800 for fuel-system work |
Full diagnostics
For the complete step-by-step diagnostic and repair guide, see P0171 — full diagnostics.
Frequently asked questions
Is it safe to drive my Honda CR-V with a P0171 code?
You can usually drive a Honda CR-V short distances with P0171, but only with caution. A lean mixture raises combustion temperatures and, over time, can damage spark plugs, oxygen sensors, and the catalytic converter. If the engine also stumbles, hesitates, or the check-engine light flashes, stop driving and have it checked, since flashing indicates active misfire.
What is the most common cause of P0171 on a Honda CR-V?
On the Honda CR-V, the most common cause of P0171 is an unmetered air leak — typically a cracked or disconnected vacuum or PCV hose that lets extra air into the engine after the MAF sensor. A dirty MAF sensor is the next most common cause. Both make the mixture read lean on Bank 1 and set the code.
How much does it cost to fix P0171 on a Honda CR-V?
Repair cost for P0171 on a Honda CR-V depends on the root cause. Replacing a cracked vacuum or PCV hose often runs about $50 to $150. Cleaning the MAF sensor may cost only the price of cleaner, while a new MAF sensor typically runs $150 to $350 installed. Fuel-system repairs such as injectors or a fuel pump can reach $400 to $800 or more.