P0171 on a 2023 Honda Cr V

P0171 means the engine computer is adding more fuel than normal on bank 1 because it sees too much air or not enough fuel.

Not your vehicle? See general P0171 info.

Most common causes on the 2023 Honda Cr V

Ranked from 506 NHTSA owner complaints filed for this vehicle.

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1
Failing high-pressure fuel pump (recall-documented cracked solenoid core)
High severity
A 2023-2025 CR-V recall (NHTSA 24V-763) covers a high-pressure fuel pump defect that cracks at the solenoid core, causing fuel pressure/delivery loss; several owners of this exact vehicle reported the recall along with pressure-related stalling and power loss consistent with a lean condition.
Reported in 6 NHTSA complaints
Parts:fuel pump
2
Failing fuel injector
Medium severity
One owner's dealer diagnosed a failed fuel injector after a sudden highway power loss, which can starve a cylinder and skew the bank's fuel trim lean.
Reported in 1 NHTSA complaint
Parts:fuel injector
3
Vacuum or intake air leak
Medium severity
Unmetered air drawn in after the MAF sensor (cracked hose, loose intake boot) richens the PCM's fuel correction and reads lean.
Common cause
4
Dirty or failing mass airflow (MAF) sensor
Medium severity
A contaminated or drifting MAF under-reports incoming air, so the PCM under-fuels and trims lean to compensate.
Common cause
Parts:mass airflow sensor
5
Clogged fuel filter
Medium severity
Restricted fuel flow to the rail drops delivered fuel volume under load, producing a lean trim especially at higher RPM.
Common cause
Parts:fuel filter
6
Intake manifold gasket leak
Medium severity
A leaking manifold gasket admits extra unmetered air directly into the cylinders, same effect as a vacuum leak.
Common cause
Parts:intake manifold gasket
7
Stuck-open PCV valve
Low severity
A PCV valve stuck open pulls excess crankcase air into the intake, leaning the mixture particularly at idle.
Common cause
Parts:PCV valve

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These causes are aggregated from NHTSA owner complaints and general repair knowledge — this is not a diagnosis. P0171 on your car still needs shop confirmation before any repair.

Common symptoms

Check engine light
Rough idle
Hesitation
Surging idle
Poor fuel economy

What to check before replacing parts

Review short- and long-term fuel trims on bank 1

Look for: High positive trims (commonly worse at idle, improving with RPM) mean the computer is adding fuel to compensate for excess air or insufficient fuel — that pattern is this code's fingerprint.

Smoke-test the intake

Look for: Smoke escaping (or a hiss you can hear) at intake boots, gaskets, or vacuum hose connections confirms unmetered air is entering after the MAF sensor, which is the most common cause of a lean code.

Inspect the PCV hoses and valve

Look for: A cracked, split, or disconnected PCV hose, or a PCV valve stuck open, draws in extra unmetered air the same way a vacuum leak does.

Clean and test the MAF sensor

Look for: Visible dirt or oil film on the sensor element, or a grams/second reading that doesn't track expected airflow for RPM, means the MAF is under-reporting air and causing the computer to under-fuel.

Verify fuel pressure

Look for: Pressure below spec (weak pump, clogged filter, failing regulator) starves the engine of fuel and produces the same lean trim pattern as a vacuum leak — rule it out before chasing leaks.

Rather have a pro handle it? Find a vetted local mechanic.

Matching symptoms

Car Runs Rough