P2000NOx Adsorber Efficiency Below Threshold (Bank 1)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- A NOx adsorber (lean NOx trap) collects nitrogen oxides while a lean-running engine produces them and turns them into nitrogen during short rich purges. P2000 reports that the trap on bank 1 no longer stores or converts enough NOx; CARB wants this flagged before tailpipe NOx passes a fixed multiple of the standard. Chrysler documents the code on 2007 to 2011 Ram 2500/3500 pickups with the 6.7 L Cummins: bulletin 25-001-13 links it, often together with P2A00/P2A01, to sooted oxygen sensors has both sensors cleaned or replaced and a heat shield added, while 18-012-12 brings revised engine software for P2000 and other codes on the 2011 trucks. Sulphur poisoning, thermal ageing or purges that never complete are further reasons. The truck usually drives normally, but NOx output rises.
- What you may notice
- Malfunction indicator lamp on
- Often accompanied by oxygen sensor codes P2A00/P2A01
- No noticeable change in driveability
- Likely causes
- LikelySooted or drifting oxygen sensors that misjudge trap loading and purges
- PossibleNOx trap poisoned by sulphur or aged by heat
- PossibleEngine software that sets the code without a real fault (update available on some models)
- RareRich purges or desulphation not completed, e.g. because of short trips
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €100 – €3,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.