P0402 on Honda: How to Diagnose & Fix
Exhaust Gas Recirculation Flow Excessive
1 Honda model · 1 documented issue · $100-$450 repair
P0402 on Honda by model: symptoms, diagnosis and fix
On the D17 the EGR passages inside the intake manifold pack with carbon over time. Restricted flow sets P0401 (insufficient EGR flow), while a stuck/dirty valve can set P0402 (excessive flow). Owners chase this because a new EGR valve alone rarely fixes it — the manifold ports themselves are blocked. Symptoms include the CEL, hesitation, and a mild rough idle. Honda addressed the same carbon-blockage phenomenon (Civic/Accord/Odyssey) in TSB 99-085, which requires manifold removal to clean the ports.
Common Symptoms
- Check-engine light with P0401 or P0402
- Hesitation or stumble under light acceleration
- Rough or shaky idle
- Occasional idle surging
- Code returns after replacing only the EGR valve
How to Fix
Remove the intake manifold and physically clean the EGR passages and valve seat per TSB 99-085; clean or replace the EGR valve. Verify by powering the valve open at idle — the engine should stall if the ports are clear. A simple valve swap without cleaning the ports usually returns the code.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Honda 18011-PLM-A01 EGR valve setOEMHonda 18011-PLM-A01 (replaces A00)
Replace the EGR valve only after testing proves it sticks or its lift sensor/actuator fails Fitment/availability: 2001-2005 Civic D17 catalog branch with trim/year differences; enter VIN. Cleaning restricted passages remains necessary wh…
- Genuine Honda 18715-PB2-000 EGR-valve gasketOEMHonda 18715-PB2-000
Required replacement gasket whenever the EGR valve is removed for inspection, cleaning or replacement Fitment/availability: Confirm VIN and matching valve/manifold; install on clean sealing surfaces to Honda torque specification.
- Genuine Honda 17055-PLD-004 front injector-base/intake-manifold gasketOEMHonda 17055-PLD-004
Required sealing branch when the D17 intake assembly is removed to clean passages Fitment/availability: Cataloged for the stated 2001-2005 Civic D17 mainstream branches; enter VIN and confirm the exact manifold stack and all required sea…
- Genuine Honda 16176-PMR-A01 throttle-body gasketOEMHonda 16176-PMR-A01
Enter VIN because alternate gasket branches can exist; do not buy unless the repair procedure removes t
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Sources for this issue (3)
P0402 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0402 mean on a Honda?
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 Honda it is documented across 1 model: Civic.
What are the most common causes of P0402?
The most common causes of P0402 are: 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. The specific cause varies by vehicle.
How much does it cost to fix P0402 on a Honda?
Published repair estimates on Honda range from $100 to $450 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0402 on a different make?
View P0402 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.