P2BAD on Land Rover: How to Diagnose & Fix
NOx Exceedance - SCR Catalyst Conversion Efficiency
1 Land Rover model · 1 documented issue · 1 critical · $2,000-$5,000 repair
P2BAD on Land Rover by model: symptoms, diagnosis and fix
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.
Common Symptoms
- White smoke from exhaust
- Gradual coolant loss with no external leak
- Sweet smell from exhaust
- Rough running or misfires
- Overheating
- Milky residue in coolant overflow
How to Fix
Replace the EGR cooler with the updated JLR design. Flush the cooling system and check for coolant contamination in the intake and exhaust. Inspect the DPF for coolant damage. Some owners delete the EGR system entirely (off-road use only). Budget for 8-12 hours labor.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- LR018752 genuine left EGR valve and cooler assemblyOEMLR018752.LRC
Replace a pressure-test-confirmed failed left EGR cooler/valve assembly on the matching 3.0 diesel branch Fitment/availability: Left-hand 3.0 TDV6 Discovery 4/5 listing, 2009-2019 family. Confirm VIN, engine generation and supersession; …
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Owner tips & cautions
- WarningMonitor coolant level weekly on TDV6/SDV6 models. Any unexplained coolant loss should be investigated immediately — EGR cooler failure can destroy the engine.
P2BAD 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 P2BAD mean on a Land Rover?
P2BAD stands for "NOx Exceedance - SCR Catalyst Conversion Efficiency." This code, found on modern diesels with selective catalytic reduction (SCR), means the system has detected that tailpipe NOx (nitrogen oxide) emissions have exceeded the legal limit because the SCR catalyst isn't converting them efficiently enough. The SCR system injects diesel exhaust fluid (DEF/AdBlue) over a catalyst to chemically break down NOx, and NOx sensors before and after the catalyst measure how well it's working. When the measured conversion falls below the required threshold, the computer flags this code, often triggering warning lights, a countdown to reduced power, or limp mode. Common roots are contaminated or low-quality DEF, a degraded catalyst, or faulty NOx sensors. On Land Rover it is documented across 1 model: Discovery.
What are the most common causes of P2BAD?
The most common causes of P2BAD are: Contaminated, diluted, or low-quality diesel exhaust fluid (DEF), Faulty NOx sensor (upstream or downstream), Degraded, aged, or contaminated SCR catalyst, Faulty or clogged DEF/reductant injector, Insufficient DEF dosing or low DEF quantity, Exhaust leak before or within the SCR system, Faulty EGR system raising engine-out NOx, Wiring or connector faults to NOx sensors. The specific cause varies by vehicle.
How much does it cost to fix P2BAD on a Land Rover?
Published repair estimates on Land Rover range from $2,000 to $5,000 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 P2BAD on a different make?
View P2BAD 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.