P0404 on Toyota
Exhaust Gas Recirculation Circuit Range/Performance
P0404 on Toyota vehicles indicates exhaust gas recirculation circuit range/performance. Au7o has documented this code across 8 Toyota models — most commonly on 4Runner, Avalon, Highlander. 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 Toyota range from $150 to $15,000, 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 Toyota by Model
Toyota 4Runner(1 issue)
- Frame Rust and Corrosion2010-2019
The frame on 4Runners, especially in northern/salt belt states, can develop severe rust and corrosion. This is a safety concern as the frame provides structural integrity. Toyota had a frame replacement program for some Tacomas/Tundras but 4Runners were not included.
Toyota Avalon(1 issue)
- 6-Speed Automatic Transmission Torque Converter Shudder2013-2018
The Aisin U660E 6-speed automatic develops torque converter lockup shudder at 25-50 mph under light throttle. The lockup clutch material degrades, causing vibration during cruising. Fluid degradation accelerates the problem.
Toyota Highlander(1 issue)
- Hybrid Battery Pack Degradation and Failure2006-2013
Highlander Hybrid NiMH battery packs degrade over time, with individual cells failing after 8-12 years or 150,000+ miles. Failed cells cause reduced fuel economy, loss of hybrid assist, and eventual inability to start the vehicle.
Toyota Land Cruiser(1 issue)
- KDSS (Kinetic Dynamic Suspension System) Hydraulic Leaks2008-2021
The KDSS system uses hydraulic cylinders connected to the front and rear stabilizer bars to improve both on-road handling and off-road articulation. The hydraulic lines, cylinders, and accumulator develop leaks over time, causing KDSS warning lights and degraded handling.
Toyota Prius(1 issue)
- Hybrid Battery Pack (HV Battery) Failure2004-2015
Gen 2 (2004-2009) and Gen 3 (2010-2015) Prius NiMH battery packs commonly fail between 8-15 years. Individual cell degradation causes voltage imbalances, triggering warning lights and reduced performance. Battery cooling fan clogging accelerates failure.
Toyota Prius V(1 issue)
- EGR Cooler Condensation and Engine Intake Carbon Buildup2012-2017
The Prius V uses an EGR (Exhaust Gas Recirculation) cooler that produces condensation during short trips and cold weather driving. This condensation mixes with exhaust gases to form carbon deposits in the intake manifold and on the intake valves. Over time, the carbon buildup restricts airflow, causing rough idle and reduced fuel economy. The EGR valve itself can also become stuck from carbon accumulation. This is more prevalent in cold climate Prius V models driven primarily for short trips.
Toyota Sienna(1 issue)
- Dashboard Cracking and Melting2007-2010
2nd-gen Sienna dashboards are notorious for cracking, warping, and developing a sticky/melting surface, especially in hot climates. The dashboard material degrades from UV exposure and heat, creating a hazardous glare and releasing a sticky residue.
Toyota Tundra(1 issue)
- Cam Tower Oil Leak2007-2021
The 5.7L iForce V8 engine is known for developing oil leaks at the cam tower due to Toyota's use of gray RTV silicone sealant instead of a proper gasket from the factory. The sealant degrades over time, particularly at the rear of the cam towers where the engine is slanted.
Looking for P0404 on a different make?
View P0404 across all makes →Frequently Asked Questions
What does P0404 mean on Toyota?▼
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 Toyota specifically, this code is documented across 8 models.
What causes P0404 on Toyota vehicles?▼
Common causes on Toyota: 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 Toyota?▼
Repair costs on Toyota range from $150 to $15,000, depending on the specific model and root cause.
Which Toyota models have P0404 documented?▼
Au7o has documented P0404 on 8 Toyota models: 4Runner, Avalon, Highlander, Land Cruiser, Prius, Prius V, Sienna, Tundra.