P0402 on Hyundai
Exhaust Gas Recirculation Flow Excessive
P0402 on Hyundai vehicles indicates exhaust gas recirculation flow excessive. Au7o has documented this code across 2 Hyundai models — most commonly on Accent, Kona. P0402 means the Exhaust Gas Recirculation (EGR) system is flowing too much exhaust back into the intake. The EGR system intentionally routes a small amount of inert exhaust gas into the engine to lower combustion temperatures and reduce nitrogen-oxide emissions, but the flow must be metered precisely. When the PCM determines the flow is excessive — often because the EGR valve is stuck open or letting gas through when it shouldn't — it sets this code. Too much EGR can cause rough idle, stalling, hesitation, and a check engine light. Typical repair costs on Hyundai range from $110 to $1,400, depending on the specific model and root cause.
Common Causes of P0402
- •EGR valve stuck open or not closing fully
- •Failed or sticking EGR valve diaphragm/solenoid
- •Carbon buildup holding the EGR valve open
- •Faulty EGR position or differential pressure (DPFE) sensor
- •Leaking EGR valve gasket or pintle seat
- •Vacuum control or solenoid fault commanding EGR open
- •Wiring or connector problems in the EGR control circuit
P0402 on Hyundai by Model
Hyundai Accent(1 issue)
- Crankshaft Position Sensor Failure2012-2022
The crankshaft position sensor on the 1.6L Gamma engine in the Accent fails prematurely, causing no-start conditions, intermittent stalling, and rough running. The sensor's internal hall-effect element degrades from heat exposure near the engine block. Common failure between 60,000-100,000 miles.
Hyundai Kona(1 issue)
- IVT/CVT Judder and Droning Noise2018-2025
The Kona with the 2.0L engine uses Hyundai's IVT (Intelligent Variable Transmission, a chain-driven CVT) that can develop juddering at low speeds and a droning noise at highway speeds. The transmission fluid degrades faster than expected, and the chain and pulleys wear. TSB 21-AT-005 addresses judder concerns.
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View P0402 across all makes →Frequently Asked Questions
What does P0402 mean on Hyundai?▼
P0402 stands for "Exhaust Gas Recirculation Flow Excessive." P0402 means the Exhaust Gas Recirculation (EGR) system is flowing too much exhaust back into the intake. The EGR system intentionally routes a small amount of inert exhaust gas into the engine to lower combustion temperatures and reduce nitrogen-oxide emissions, but the flow must be metered precisely. When the PCM determines the flow is excessive — often because the EGR valve is stuck open or letting gas through when it shouldn't — it sets this code. Too much EGR can cause rough idle, stalling, hesitation, and a check engine light. On Hyundai specifically, this code is documented across 2 models.
What causes P0402 on Hyundai vehicles?▼
Common causes on Hyundai: EGR valve stuck open or not closing fully, Failed or sticking EGR valve diaphragm/solenoid, Carbon buildup holding the EGR valve open, Faulty EGR position or differential pressure (DPFE) sensor, Leaking EGR valve gasket or pintle seat. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0402 on a Hyundai?▼
Repair costs on Hyundai range from $110 to $1,400, depending on the specific model and root cause.
Which Hyundai models have P0402 documented?▼
Au7o has documented P0402 on 2 Hyundai models: Accent, Kona.