P0402 on Nissan
Exhaust Gas Recirculation Flow Excessive
P0402 on Nissan vehicles indicates exhaust gas recirculation flow excessive. Au7o has documented this code across 4 Nissan models — most commonly on 370Z, Leaf, Pathfinder. 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 Nissan range from $200 to $8,000, 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 Nissan by Model
Nissan 370Z(1 issue)
- Concentric Slave Cylinder (CSC) Failure2009-2020
The 370Z is notorious for concentric slave cylinder failures, which is integrated with the clutch release bearing inside the transmission bell housing. When it fails, the clutch cannot be disengaged. This requires transmission removal to replace, making it a costly repair.
Nissan Leaf(1 issue)
- Battery Pack Capacity Degradation2011-2023
The Nissan Leaf uses an air-cooled lithium-ion battery that degrades faster than liquid-cooled competitors. Hot climates (Arizona, Texas) accelerate degradation significantly. Early models (2011-2015) with 24 kWh packs can lose 30-40% capacity within 5-7 years. Nissan provides an 8-year/100,000-mile battery warranty covering loss below 9 bars (approximately 66% capacity) on the dashboard gauge.
Nissan Pathfinder(1 issue)
- Coolant Leak from Thermostat Housing (VQ35DE)2013-2020
The 2013-2020 Pathfinder VQ35DE engine develops coolant leaks from the thermostat housing/water outlet, typically around 60,000-100,000 miles. The plastic housing cracks or the O-ring seal degrades, causing a slow coolant leak that can lead to overheating if not addressed. This is a common issue shared with the Murano and Maxima VQ35 engines.
Nissan Sentra(1 issue)
- A/C Compressor Failure2013-2019
The A/C compressor on 2013-2019 Sentra models is known to fail prematurely, often within 60,000-80,000 miles. The compressor clutch bearings seize or the internal components disintegrate, sending metal debris throughout the A/C system. When the compressor fails internally, the entire system often needs flushing.
Looking for P0402 on a different make?
View P0402 across all makes →Frequently Asked Questions
What does P0402 mean on Nissan?▼
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 Nissan specifically, this code is documented across 4 models.
What causes P0402 on Nissan vehicles?▼
Common causes on Nissan: 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 Nissan?▼
Repair costs on Nissan range from $200 to $8,000, depending on the specific model and root cause.
Which Nissan models have P0402 documented?▼
Au7o has documented P0402 on 4 Nissan models: 370Z, Leaf, Pathfinder, Sentra.