P0171 on a 2017 Jeep Renegade

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 2017 Jeep Renegade

Ranked from 560 NHTSA owner complaints filed for this vehicle.

Sort by:

1
Weak or failing fuel pump / fuel delivery
High severity
Three owners of this exact vehicle describe the fuel pump going out or 'not enough gas going through' during a stall/power-loss event, plus a fuel gauge reading well above empty right before the car dies — all consistent with insufficient fuel delivery leaning out the mixture.
Reported in 3 NHTSA complaints
Parts:fuel pump
2
Cracked or broken intake/vacuum air lines
Medium severity
The plastic air lines off the air filter housing on this first-generation 1.4L turbo are reported to crack or snap during routine service, letting in unmetered air that leans the fuel trim.
Reported in 1 NHTSA complaint
3
Dirty or failing mass airflow (MAF) sensor
Medium severity
A contaminated or drifting MAF under-reports intake air, causing the PCM to under-fuel and trim lean.
Common cause
Parts:mass airflow sensor
4
Clogged fuel filter
Medium severity
Restricted fuel flow reduces delivered volume under load, producing a lean trim especially at higher RPM.
Common cause
Parts:fuel filter
5
Intake manifold gasket leak
Medium severity
A leaking manifold gasket admits extra unmetered air directly into the cylinders.
Common cause
Parts:intake manifold gasket
6
Exhaust leak upstream of the O2 sensor
Low severity
A leak ahead of the front oxygen sensor draws in outside air that the sensor reads as a lean condition.
Common cause
7
Stuck-open PCV valve
Low severity
A PCV valve stuck open pulls extra crankcase air into the intake, leaning the mixture 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