P0171 on a 2016 Jeep Cherokee

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 2016 Jeep Cherokee

Ranked from 1,400 NHTSA owner complaints filed for this vehicle.

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1
Weak or failing fuel pump reducing fuel pressure
High severity
A recalled/failing fuel pump on this model caused the vehicle to stall in traffic from inadequate fuel delivery, which can also register as a lean condition.
Reported in 1 NHTSA complaint
Parts:fuel pump
2
Companion bank-2 lean/catalyst codes reported alongside this code
Medium severity
One owner's scan also pulled P0174/P0175 (bank 2 lean) together with catalyst and misfire codes, consistent with a shared vacuum leak or MAF fault affecting the whole engine.
Reported in 1 NHTSA complaint
3
Vacuum or intake air leak
Medium severity
Unmetered air entering after the MAF sensor leans the mixture; check intake boots, PCV hoses, and brake booster line with smoke testing.
Common cause
4
Dirty or failing mass airflow (MAF) sensor
Low severity
An undercounting MAF sensor tells the PCM less air is entering than actually is, causing the fuel trim to compensate and read lean.
Common cause
Parts:mass airflow sensor
5
Exhaust leak upstream of the front oxygen sensor
Medium severity
A leak before the O2 sensor draws in outside air, skewing the sensor toward a lean reading.
Common cause
6
PCV valve stuck open
Low severity
An open PCV valve pulls excess, unmetered air into the intake, leaning the mixture particularly at idle.
Common cause
Parts:PCV valve
7
Intake manifold gasket leak
Medium severity
A leaking manifold gasket admits unmetered air directly into the cylinders, a common lean-code cause on aging 4-cylinder engines.
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