P0174 on Hyundai
System Too Lean (Bank 2)
P0174 on Hyundai vehicles indicates system too lean (bank 2). Au7o has documented this code across 6 Hyundai models — most commonly on Excel, Genesis Coupe, Palisade. P0174 means the engine computer detected that the air-fuel mixture on Bank 2 (the side of the engine with cylinder 2) is running too lean — too much air relative to fuel. The computer monitors this through the oxygen/air-fuel sensors and fuel trims; when it has to add a large amount of extra fuel to compensate and still can't reach the target, it flags the mixture as too lean. A lean condition can cause rough idle, hesitation, or misfires, and over time can raise combustion temperatures. Because it's Bank 2 specific, an unmetered air leak on that bank or a fuel delivery shortfall is typical. Typical repair costs on Hyundai range from $50 to $4,000, depending on the specific model and root cause.
Common Causes of P0174
- •Vacuum or intake air leak (hoses, gaskets, PCV)
- •Dirty or failing mass airflow (MAF) sensor
- •Weak fuel pump or restricted fuel filter (low fuel pressure)
- •Clogged or underperforming fuel injectors
- •Leaking intake manifold or throttle body gasket
- •Faulty or contaminated oxygen / air-fuel sensor
- •Exhaust leak upstream of the oxygen sensor
- •Stuck-open EGR valve
P0174 on Hyundai by Model
Hyundai Excel(1 issue)
- Head Gasket Failure (Mitsubishi G4DJ/G4EK)1990-1994
The Hyundai Excel uses Mitsubishi-derived 1.5L engines (G4DJ and G4EK) that are prone to head gasket failure. The gasket material deteriorates from heat cycling and age, causing coolant leaks, overheating, and combustion gas intrusion into the cooling system. The Excel was a budget vehicle and many owners deferred maintenance, accelerating gasket failure. While the repair is straightforward on this simple engine, the low value of the vehicle often makes head gasket replacement uneconomical.
Hyundai Genesis Coupe(1 issue)
- Excessive Oil Consumption - 3.8L Lambda V62013-2016
The 3.8L Lambda V6 in the BK2 Genesis Coupe consumes oil at an excessive rate, often 1 quart every 1,500-2,500 miles. The issue is related to piston ring design and valve stem seal degradation. Some engines require a quart of oil every 1,000 miles. Hyundai acknowledged the issue but did not issue a recall.
Hyundai Palisade(1 issue)
- Oil Dilution / Gasoline Contamination in Engine Oil2020-2024
The 3.8L Lambda II V6 in the Palisade can suffer from fuel diluting the engine oil, particularly in cold climates with short trips. The GDI system can allow unburned fuel past the piston rings during cold starts. Oil level rises above the full mark and smells of gasoline. Hyundai released a software update to address the issue.
Hyundai Santa Fe(1 issue)
- Excessive Oil Consumption - 2.4L GDI Engine2013-2019
The 2.4L GDI engine in Santa Fe models can consume excessive oil, sometimes 1 quart every 1,000-1,500 miles. This is related to carbon buildup on piston rings and intake valves inherent to GDI engines. Low oil can lead to engine damage if not monitored. Hyundai has an oil consumption test procedure for affected vehicles.
Hyundai Scoupe(1 issue)
- Head Gasket Failure (Shared Excel Platform)1991-1995
The Hyundai Scoupe shares its engine and platform with the Excel, inheriting the same head gasket weakness from the Mitsubishi-derived 1.5L engine (G4EK). The head gasket deteriorates with heat cycling, causing coolant leaks and overheating. The Scoupe Turbo model (1993-1995) is even more susceptible due to the added heat and pressure from forced induction. Regular cooling system maintenance is essential for longevity.
Hyundai XG350(1 issue)
- Intake Manifold Gasket Leak2002-2005
The 3.5L V6 intake manifold gaskets deteriorate causing vacuum leaks, rough idle, and lean running conditions. Upper plenum gasket is most common failure point. Can trigger multiple misfire codes.
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View P0174 across all makes →Frequently Asked Questions
What does P0174 mean on Hyundai?▼
P0174 stands for "System Too Lean (Bank 2)." P0174 means the engine computer detected that the air-fuel mixture on Bank 2 (the side of the engine with cylinder 2) is running too lean — too much air relative to fuel. The computer monitors this through the oxygen/air-fuel sensors and fuel trims; when it has to add a large amount of extra fuel to compensate and still can't reach the target, it flags the mixture as too lean. A lean condition can cause rough idle, hesitation, or misfires, and over time can raise combustion temperatures. Because it's Bank 2 specific, an unmetered air leak on that bank or a fuel delivery shortfall is typical. On Hyundai specifically, this code is documented across 6 models.
What causes P0174 on Hyundai vehicles?▼
Common causes on Hyundai: Vacuum or intake air leak (hoses, gaskets, PCV), Dirty or failing mass airflow (MAF) sensor, Weak fuel pump or restricted fuel filter (low fuel pressure), Clogged or underperforming fuel injectors, Leaking intake manifold or throttle body gasket. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0174 on a Hyundai?▼
Repair costs on Hyundai range from $50 to $4,000, depending on the specific model and root cause.
Which Hyundai models have P0174 documented?▼
Au7o has documented P0174 on 6 Hyundai models: Excel, Genesis Coupe, Palisade, Santa Fe, Scoupe, XG350.