P2000

NOx Adsorber Efficiency Below Threshold Bank 1

P2000 is a generic OBD-II powertrain diagnostic trouble code: NOx Adsorber Efficiency Below Threshold Bank 1. It is logged by the engine control unit when the scr/adblue monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.

Code
P2000
Group
Powertrain
System
SCR/AdBlue
Severity
Warning (MIL on)
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What P2000 means

P2000 indicates that the NOx adsorber, also called a NOx trap or Lean NOx Trap, on bank 1 is operating below the minimum efficiency threshold. NOx traps are used on lean-burn gasoline and many diesel applications to store nitrogen oxides during lean operation and then reduce them to nitrogen and oxygen during periodic rich regeneration events. The ECM evaluates trap efficiency using NOx sensor data and stored regeneration behavior; bank 1 refers to the side of the engine containing cylinder number one.

When the module concludes that the trap can no longer store and convert NOx effectively, it sets P2000. This can stem from trap saturation from frequent short trips that prevent full regeneration, insufficient exhaust temperature to trigger regeneration, catalyst aging or thermal damage, sulfur poisoning from high-sulfur fuel, a faulty NOx sensor, or upstream issues such as a failing EGR valve or clogged oxidation catalyst.

Diagnosis should begin with retrieving codes and freeze frame data, checking for exhaust leaks that could dilute sensor readings, and confirming NOx sensor accuracy before condemning the trap. Where supported, a desulfation or forced regeneration procedure should be attempted before replacement.

Common causes

Most-frequently reported root causes when P2000 is logged.

  • 1
    Aged or thermally damaged NOx trap with reduced storage capacity.
  • 2
    Sulfur poisoning of the trap substrate from high-sulfur fuel.
  • 3
    NOx trap saturation from frequent short trips preventing full regeneration.
  • 4
    Insufficient exhaust temperature failing to trigger trap regeneration.
  • 5
    Faulty NOx sensor providing inaccurate efficiency data.
  • 6
    Exhaust leak affecting sensor readings near the trap.
  • 7
    Malfunctioning EGR valve or clogged oxidation catalyst upstream of the trap.

Symptoms drivers notice

Check engine light illuminated.
Increased tailpipe NOx emissions, likely failing an emissions inspection.
Possible reduced power or occasional limp-mode on some applications.
Slight reduction in fuel economy if regeneration cycles are extended.
Related NOx sensor codes may accompany P2000.

How to diagnose P2000

A typical diagnostic flow when this code is present.

  1. 1
    Retrieve all DTCs and freeze frame data and note any accompanying NOx sensor codes.
  2. 2
    Inspect for exhaust leaks near the NOx trap that could affect sensor readings.
  3. 3
    Check NOx sensor operation using live data, comparing readings during lean and rich conditions.
  4. 4
    Verify fuel quality and confirm low-sulfur fuel is being used as specified.
  5. 5
    Review regeneration frequency and inspect the EGR valve and oxidation catalyst for upstream faults.
  6. 6
    If supported, perform a desulfation or forced regeneration procedure and re-evaluate.
  7. 7
    Replace the NOx trap only if efficiency remains low after sensor, leak, and regeneration checks pass.

Vehicles where we've handled P2000

Platforms in our catalogue with confirmed P2000 coverage.

BMW 320D
2016
MB GLE350 30D

Related powertrain codes

Frequently asked questions

Is P2000 the same as a catalytic converter fault?

Not exactly. A NOx trap is a specialized catalyst distinct from a standard three-way catalyst. P0420 covers three-way catalyst efficiency, while P2000 is specific to the NOx storage function.

Can better fuel fix P2000?

If sulfur poisoning from high-sulfur fuel is the cause, switching to low-sulfur fuel and performing a desulfation procedure may restore trap efficiency.

How is the NOx trap different from an SCR system?

A NOx trap stores and then reduces NOx during rich regeneration without a separate reductant. SCR systems inject urea (DEF) to convert NOx. They are separate aftertreatment technologies.

Will P2000 cause an emissions test failure?

Yes. Reduced trap efficiency raises tailpipe NOx, which typically causes failure on emissions tests that measure or check for NOx-related faults.

Disabling P2000 in software

RaceTune can permanently disable P2000 — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.

Permanent
The monitor is disabled in the ECU itself — not just cleared. It cannot return.
Tailored to your file
Each patch is matched to your specific software version — never a one-size-fits-all file.
Reversible
The original file is always preserved. Reflash the stock to return the ECU to factory state.

ECU families we can disable P2000 on

We hold the DaVinci A2L disable definitions for these families, so the exact P2000 path and mask addresses are mapped. verified marks a confirmed disable definition. We support many more — upload your file and our identifier will match it automatically.

  • Bosch EDC17C50 verified
  • Bosch EDC17C56 verified
  • Bosch EDC17C66 verified
  • Bosch EDC17CP57 verified
  • Bosch MD1CP002 verified
  • Bosch MD1CP004 verified
  • Bosch MD1CS001 verified
  • Bosch MG1CP002 verified

Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.

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