P0402 on Jaguar: How to Diagnose & Fix
Exhaust Gas Recirculation Flow Excessive
1 Jaguar model · 1 documented issue · $400-$3,000 repair
P0402 on Jaguar by model: symptoms, diagnosis and fix
On the 2005-2009 X350 XJ 2.7 diesel the twin EGR valves and the plastic inlet 'Y-piece' clog with soot. A valve stuck open feeds carbon back into the intake, restricts airflow and triggers 'Restricted Performance' limp mode; a valve stuck or leaking oil has been linked by owners and specialists to turbocharger bearing failure, and a replacement turbo will fail again if the EGR is not fixed at the same time. Threads on the XJ, XF and Discovery 3/Range Rover Sport (same engine) all document the same pattern.
Common Symptoms
- 'Restricted Performance' message and limp mode
- Black smoke and loss of power under load
- Rough idle after warm-up
- Whining turbo or blue smoke after EGR fault
How to Fix
No recall. Clean or replace the EGR valves (both banks) and the inlet Y-piece, clear the intake of carbon, and check the turbo for shaft play before returning the car to service. Some owners fit EGR blanking kits (not road-legal in all markets). Expect roughly $400-1,200 for EGR work; add $1,500-3,000 if a turbo has already been damaged.
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 Jaguar?
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 Jaguar it is documented across 1 model: XJ.
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 Jaguar?
Published repair estimates on Jaguar range from $400 to $3,000 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.