2007-2018 Honda CR-V
P0171
System Too Lean (Bank 1) - Honda CR-V
Honda CR-V K24 engines develop PCV valve diaphragm tears and intake manifold runner gasket leaks - both cause lean Bank 1 codes
Moderate Severity $30-$420 Typical Repair Check PCV Valve First
Plain English

What P0171 means for your CR-V

The Honda CR-V's 2.4L K24 engine has a PCV valve that uses a small diaphragm. As the diaphragm ages, it tears or holds open, creating a measurable unmetered air leak. CR-Vs from 2007-2014 are the most affected. The fix is a $20-$40 PCV valve and 10 minutes of work. A smaller subset of P0171 CR-Vs have intake manifold runner control gasket leaks or contaminated MAF sensors.

🎯 Top Causes on the Honda CR-V

45%
#1 CAUSE
PCV Valve Diaphragm Failure
The K24's PCV valve sits on the valve cover and uses a one-way diaphragm. When it tears, intake vacuum pulls unmetered air through the valve cover at all times - exactly the behavior that triggers P0171. Replacement is straightforward: pull the old valve, install a Honda OEM PCV (around $25), reconnect the hose. Many CR-V owners report a clean fuel trim within one drive cycle.
PCV Valve
$20-$40
Labor (shop)
$30-$60
Total
$20-$100
30%
#2 CAUSE
Intake Manifold Runner Gasket
The K24's intake manifold has a runner control system with its own gaskets. After 100k miles these harden and leak air. Symptoms: rough cold idle plus P0171, and sometimes P2004 or P2008 alongside. Replacement requires pulling the intake plenum to access the runner gaskets - more time than a PCV valve.
Gasket Kit
$45-$90
Labor
$220-$340
Total
$265-$430
25%
#3 CAUSE
Dirty MAF Sensor
K24 MAF sensors collect oil mist from the PCV path. A contaminated MAF underreports airflow. Clean with CRC MAF cleaner first - many CR-V P0171 cases clear after cleaning. If cleaning does not restore correct g/s readings, replace with OEM Denso.
MAF Cleaner
$8 DIY
OEM MAF
$160-$210
w/Labor
$210-$300

🚚 Most Affected CR-V Model Years

YearEngineTrimTypical MileageNotes
2007-20112.4L K24Z1/K24Z6LX, EX, EX-L90k-140kPCV valve diaphragm most common
2012-20142.4L K24Z7LX, EX, EX-L80k-130kSame PCV behavior plus runner gasket
2015-20182.4L K24W (Earth Dreams)LX, EX, EX-L, Touring70k-110kDirect injection adds carbon buildup risk

⚠ Is It Safe to Drive Your CR-V with P0171?

Yes - typical CR-V P0171 is safe to drive while you schedule the repair.

Unless paired with misfires or hesitation under load, a CR-V P0171 is a maintenance issue, not an emergency. Continue driving normally for a few weeks while you replace the PCV valve. Watch for hard cold starts or rough idle as signs the leak is getting worse.

🔧 How to Diagnose P0171 on a Honda CR-V

  • Pull and inspect the PCV valve. Open the hood and locate the PCV valve on top of the valve cover (small plastic housing). Disconnect the hose, unscrew or unclip the valve, and shake it. A good PCV valve rattles. A failed one is silent, sticky, or has visible cracks in the diaphragm. Replace with Honda OEM PCV before anything else.
  • Read LTFT at idle and at 2500 RPM. LTFT above +18% at idle that drops below +8% at 2500 RPM = vacuum leak. Steady high LTFT at all RPM = MAF or fuel issue. Pinpointing this saves hundreds in unnecessary parts.
  • Inspect the intake boot and small hoses. Inspect the rubber intake boot from MAF to throttle body for cracks. Also check the small evap purge hose - on K24s, the purge solenoid hose hardens and splits, mimicking a PCV leak. A flashlight inspection takes 5 minutes.
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❓ P0171 Honda CR-V FAQs

How much does P0171 cost to fix on a Honda CR-V?

PCV valve: $20-$100. Intake runner gasket: $265-$430. MAF clean: $8 DIY. Most CR-V P0171s are resolved by the PCV valve.

Is the CR-V PCV valve a common failure?

Yes. Honda K24 PCV valves are a known wear item after 80k-100k miles. Some dealerships recommend preemptive replacement at the 100k service.

Will P0171 cause my CR-V to fail emissions?

Yes, a stored P0171 is a non-readiness or hard-fail in most states, depending on local rules. Fix and clear the code, then complete a full drive cycle before testing.

Can I just clear the code and ignore it?

No. The code will return once the ECM detects the lean condition again. The underlying leak still raises combustion temperature and stresses the catalysts.

See all P0171 causes and vehicles ->

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