P0402 on SEAT
Exhaust Gas Recirculation Flow Excessive
P0402 on SEAT vehicles indicates exhaust gas recirculation flow excessive. Au7o has documented this code across 2 SEAT models — most commonly on Ibiza, Leon. 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 SEAT range from $250 to $1,500, 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 SEAT by Model
SEAT Ibiza(1 issue)
- 1.6 TDI (EA189) EGR Valve Failure - Aggravated by Dieselgate Emissions Fix2009-2016
The 1.6 TDI (and related 1.2/1.9 TDI) diesels are prone to EGR valve clogging and failure, with carbon build-up causing limp mode, black smoke and power loss. On the EA189 engine the EGR shares its casing with a heat exchanger/cooler, making it an expensive component to replace, and it is awkwardly located at the back of the engine raising labour costs. Crucially, the issue became much more prevalent after the Dieselgate NOx emissions software fix (rolled out for SEAT 1.6/2.0 TDI from January 2016 and 1.2 TDI from April 2016) - the recalibration increased EGR duty cycle and many owners reported EGR failures shortly after the 'fix' was applied. VW Group has in some cases refunded owners for post-fix EGR failures.
SEAT Leon(1 issue)
- EA189 TDI Diesel: EGR/DPF Clogging and Post-Dieselgate Oil Dilution2009-2015
Diesel Leons (1.6 TDI and 2.0 TDI) using the EA189 engine - the engine at the centre of the Dieselgate emissions scandal - are widely reported for EGR valve and EGR-cooler clogging with soot and DPF (diesel particulate filter) blockages, especially on short-trip/urban driving that prevents the filter reaching regeneration temperature. After the mandated emissions 'fix', many owners additionally reported worsened DPF behaviour and oil dilution (diesel washing into the sump during frequent active regens), requiring more frequent oil changes.
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View P0402 across all makes →Frequently Asked Questions
What does P0402 mean on SEAT?▼
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 SEAT specifically, this code is documented across 2 models.
What causes P0402 on SEAT vehicles?▼
Common causes on SEAT: 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 SEAT?▼
Repair costs on SEAT range from $250 to $1,500, depending on the specific model and root cause.
Which SEAT models have P0402 documented?▼
Au7o has documented P0402 on 2 SEAT models: Ibiza, Leon.