P0401 on Land Rover
Exhaust Gas Recirculation Flow Insufficient
P0401 on Land Rover vehicles indicates exhaust gas recirculation flow insufficient. Au7o has documented this code across 2 Land Rover models — most commonly on Defender, Discovery. 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 Land Rover range from $300 to $5,000, 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 Land Rover by Model
Land Rover Defender(1 issue)
- DPF / EGR / VNT Turbo Carbon-Choke (2.2 EU5 Emissions Trio)2012-2016
The Euro 5 2.2 added a DPF, and the EGR/DPF/variable-vane turbo behave as one interlinked system that clogs with soot on short-trip, low-speed use. A carboned EGR dumps extra soot into the DPF, the DPF blocks and forces failed regens (diesel washes into the sump and the oil level rises), and carbon from the EGR/blow-by builds on the VNT turbo vanes so they stick and the engine drops into underboost/limp mode. The EGR cooler can also crack internally and let coolant into the exhaust circuit. This is the cluster of faults that puts a 2.2 into limp mode again and again.
Land Rover Discovery(1 issue)
- EGR Cooler Failure and Coolant Leak (TDV6/SDV6)2010-2018
The EGR cooler on the 3.0L TDV6 and SDV6 diesel engines develops internal cracks that allow coolant to leak into the exhaust system. This causes white smoke from the exhaust, gradual coolant loss, and can contaminate the DPF. In the worst case, coolant enters the combustion chambers and causes hydrolock. This is considered one of the most serious diesel Discovery failures.
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View P0401 across all makes →Frequently Asked Questions
What does P0401 mean on Land Rover?▼
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 Land Rover specifically, this code is documented across 2 models.
What causes P0401 on Land Rover vehicles?▼
Common causes on Land Rover: 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 Land Rover?▼
Repair costs on Land Rover range from $300 to $5,000, depending on the specific model and root cause.
Which Land Rover models have P0401 documented?▼
Au7o has documented P0401 on 2 Land Rover models: Defender, Discovery.