P0401 on Jaguar
Exhaust Gas Recirculation Flow Insufficient
P0401 on Jaguar vehicles indicates exhaust gas recirculation flow insufficient. Au7o has documented this code across 1 Jaguar model — most commonly on XJ. This code means the Exhaust Gas Recirculation (EGR) system is not flowing enough exhaust back into the engine. The EGR system recirculates a small amount of exhaust into the intake to lower combustion temperatures and reduce nitrogen oxide (NOx) emissions; the computer has determined the actual flow is below what it commanded. The most common reason is carbon buildup clogging the EGR valve or its passages. You may notice pinging/knocking, rough idle, or a check engine light, and the car will fail emissions testing. Typical repair costs on Jaguar range from $400 to $3,000, depending on the specific model and root cause.
Common Causes of P0401
- •Carbon buildup clogging the EGR valve or passages
- •Stuck or faulty EGR valve
- •Blocked or restricted EGR ports/tubes
- •Faulty EGR temperature or position sensor
- •Faulty DPFE/EGR pressure sensor (on applicable systems)
- •Vacuum leak or failed vacuum control (vacuum-operated EGR)
- •Wiring or connector problems at the EGR valve
P0401 on Jaguar by Model
Jaguar XJ(1 issue)
- 2.7 TDV6 EGR Valve Sticking and Inlet Y-Piece Carbon Blockage Causing Restricted Performance and Turbo Bearing Failure2005-2009
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.
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View P0401 across all makes →Frequently Asked Questions
What does P0401 mean on Jaguar?▼
P0401 stands for "Exhaust Gas Recirculation Flow Insufficient." This code means the Exhaust Gas Recirculation (EGR) system is not flowing enough exhaust back into the engine. The EGR system recirculates a small amount of exhaust into the intake to lower combustion temperatures and reduce nitrogen oxide (NOx) emissions; the computer has determined the actual flow is below what it commanded. The most common reason is carbon buildup clogging the EGR valve or its passages. You may notice pinging/knocking, rough idle, or a check engine light, and the car will fail emissions testing. On Jaguar specifically, this code is documented across 1 model.
What causes P0401 on Jaguar vehicles?▼
Common causes on Jaguar: Carbon buildup clogging the EGR valve or passages, Stuck or faulty EGR valve, Blocked or restricted EGR ports/tubes, Faulty EGR temperature or position sensor, Faulty DPFE/EGR pressure sensor (on applicable systems). Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0401 on a Jaguar?▼
Repair costs on Jaguar range from $400 to $3,000, depending on the specific model and root cause.
Which Jaguar models have P0401 documented?▼
Au7o has documented P0401 on 1 Jaguar model: XJ.