P0404 on Hyundai
Exhaust Gas Recirculation Circuit Range/Performance
P0404 on Hyundai vehicles indicates exhaust gas recirculation circuit range/performance. Au7o has documented this code across 2 Hyundai models — most commonly on Accent, Kona. This code means the exhaust gas recirculation (EGR) system isn't performing within its expected range. The EGR valve routes a metered amount of exhaust gas back into the intake to lower combustion temperatures and reduce nitrogen-oxide emissions, and the computer monitors the valve's actual position versus what it commanded. When the valve sticks, moves incorrectly, or the feedback doesn't match the command, P0404 sets. This can cause rough idle, hesitation, pinging, and increased emissions. Typical repair costs on Hyundai range from $110 to $1,400, depending on the specific model and root cause.
Common Causes of P0404
- •Carbon buildup clogging the EGR valve or passages
- •Sticking or failed EGR valve
- •Faulty EGR position sensor
- •Corroded or loose EGR connector
- •Damaged or shorted EGR wiring
- •Vacuum leak or failed vacuum control (on vacuum-operated systems)
- •Clogged EGR cooler or tubes
- •Faulty PCM/ECM (rare)
P0404 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.
Looking for P0404 on a different make?
View P0404 across all makes →Frequently Asked Questions
What does P0404 mean on Hyundai?▼
P0404 stands for "Exhaust Gas Recirculation Circuit Range/Performance." This code means the exhaust gas recirculation (EGR) system isn't performing within its expected range. The EGR valve routes a metered amount of exhaust gas back into the intake to lower combustion temperatures and reduce nitrogen-oxide emissions, and the computer monitors the valve's actual position versus what it commanded. When the valve sticks, moves incorrectly, or the feedback doesn't match the command, P0404 sets. This can cause rough idle, hesitation, pinging, and increased emissions. On Hyundai specifically, this code is documented across 2 models.
What causes P0404 on Hyundai vehicles?▼
Common causes on Hyundai: Carbon buildup clogging the EGR valve or passages, Sticking or failed EGR valve, Faulty EGR position sensor, Corroded or loose EGR connector, Damaged or shorted EGR wiring. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0404 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 P0404 documented?▼
Au7o has documented P0404 on 2 Hyundai models: Accent, Kona.