Fault Family
System: Powertrain (P-Codes)
2 SAE Codes
NOx Adsorber Efficiency
Diagnostic & Technical Explanation
Code P2000 (NOx Adsorber Efficiency Below Threshold Bank 1) indicates the NOx adsorber is no longer storing and converting oxides of nitrogen at the rate the aftertreatment model expects during its periodic efficiency check. Adsorber substrate that has thermally aged or become sulfur- and lubricant-poisoned loses storage capacity first, followed by a rich-regeneration event that never fully purges the trap, and occasionally by a NOx sensor drifting enough to make a healthy trap read as inefficient.
These 2 diagnostic trouble codes share one
detection mechanism and one repair path, which is why MechanicDB groups them into a single
authored fault family rather than repeating the same explanation 2 times.
What this page does not show
This page publishes the fault mechanism and the code index. The licensed dataset adds, for
every one of the 15,886 codes, the full authored repair set (56,729 procedures in total)
with the fields deliberately withheld here:
- Procedures 2..n after the first-listed procedure
- Aftermarket parts cost ranges in USD (
est_parts_cost_min/max_usd)
- Professional labor-hour estimates (
est_labor_hours)
- Step-by-step diagnostic and repair instructions
- Replacement-part mappings and catalog lookups
- 6,637 manufacturer-specific OEM codes across 32 makes ($149 tier)