NOx Trap Efficiency Below Threshold (Bank 2)
The P2001 code means the vehicle's onboard diagnostic system has detected: NOx Trap Efficiency Below Threshold (Bank 2). This is a serious severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $800 - $2,500 (parts and labor)
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What Are the Symptoms of P2001?
- Check Engine Light illuminated
- Reduced engine power on Bank 2 cylinders
- Sulfur smell from exhaust
- Higher than normal exhaust emissions
- Failed emissions inspection
What Causes P2001? (Most Likely First)
- Degraded NOx trap catalyst on Bank 2 Very High
- Sulfur poisoning from fuel High
- Faulty downstream NOx sensor Moderate
- Exhaust leak near Bank 2 NOx trap Moderate
- PCM calibration issue Low
Can I Still Drive with P2001?
Short distances only. P2001 is rated serious severity. Keep trips short and get it diagnosed soon rather than waiting for symptoms to worsen.
Frequently Asked Questions
What does P2001 mean?
P2001 means the NOx trap catalyst on Bank 2 has fallen below its efficiency threshold, indicating it can no longer adequately reduce nitrogen oxide emissions.
Can I drive with a P2001 code?
Short-distance driving is possible, but expect reduced power and failed emissions tests. Prolonged driving risks further catalyst damage.
How much does it cost to fix P2001?
Expect $800 to $2,500 depending on whether the NOx trap needs replacement or if a sensor is the root cause.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose P2001?
-
Read freeze frame data and confirm P2001 is present
-
Compare Bank 1 and Bank 2 NOx sensor readings
-
Inspect Bank 2 NOx trap for contamination or damage
-
Check for exhaust leaks on the Bank 2 side
Sources 1
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
P2001 on Diesel, EV & Equipment
The same code ID appears across other engines and platforms. The diagnostic flow varies by manufacturer — these are the platform-specific breakdowns:
Which Vehicles Commonly Get P2001?
- 2014-2020 Ram 3500 6.7L Cummins
- 2011-2017 Ford F-350 6.7L Power Stroke
- 2012-2019 Chevrolet Silverado 3500 6.6L Duramax
- 2010-2015 Audi A3 2.0L TDI
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