P0171 on a 2021 Kia Telluride

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 2021 Kia Telluride

Ranked from 337 NHTSA owner complaints filed for this vehicle.

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1
Failing high-pressure fuel pump (HPFP) starving the fuel rail
High severity
One owner's scan tool pulled code P0087 (fuel rail pressure too low) explicitly attributed to 'a faulty high-pressure fuel pump'; another owner's dealer confirmed the HPFP, solenoid, and OCV harness had failed, a documented GDI fuel-delivery weak point that produces a lean condition.
Reported in 2 NHTSA complaints
Parts:high-pressure fuel pump
2
Oil/fuel contamination of the MAP or MAF sensor
Medium severity
One owner's complaint specifically noted 'fuel in MAP sensor' alongside shuddering/stalling symptoms, which would send an inaccurate air-charge reading to the PCM and skew fuel trim lean.
Reported in 1 NHTSA complaint
Parts:MAP sensor
3
Vacuum or intake air leak
Medium severity
A cracked hose or loose intake connection admits unmetered air after the airflow sensor, leaning the mixture.
Common cause
4
Weak low-pressure fuel pump or clogged fuel filter
Medium severity
Reduced fuel delivery to the direct-injection pump starves the system under load, producing a lean code.
Common cause
Parts:fuel pump fuel filter
5
Stuck-open PCV valve
Low severity
Extra unmetered air drawn through an open PCV valve leans the idle and low-load mixture.
Common cause
Parts:PCV valve
6
Exhaust leak upstream of the oxygen sensor
Medium severity
Outside air drawn in ahead of the sensor makes the PCM see a falsely lean exhaust reading.
Common cause
7
Intake manifold gasket leak
Medium severity
A leaking gasket lets unmetered air into the runners directly, producing a bank-specific lean code.
Common cause
Parts:intake manifold gasket

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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