P21B3
Closed Loop NOx Adsorber Control At Limit - Too High
P21B3 is an OBD-II diagnostic trouble code meaning: Closed Loop NOx Adsorber Control At Limit - Too High. Common causes: nox adsorber dirty or faulty, problems with the egr system. Estimated repair cost: $56–167.
Symptoms
- Increased fuel consumption
- Reduced engine power
- Check Engine Light Is On
- Dips during acceleration
- Unstable idling
Causes
- NOx adsorber dirty or faulty
- Problems with the EGR system
- Low fuel quality
- NOx sensor malfunction
- Exhaust system leakage
How to Fix
- Check the EGR system for clogging
- Diagnose the condition of the NOx adsorber
- Check the exhaust tract for leaks
- Test NOx sensors
- Replacing the NOx adsorber if necessary
Related codes
Error P21B3 by Vehicle Brand
FAQ
What does the P21B3 code mean?
P21B3 is an OBD-II diagnostic trouble code that indicates: Closed Loop NOx Adsorber Control At Limit - Too High
What causes a P21B3 error code?
The most common causes of P21B3 include: NOx adsorber dirty or faulty; Problems with the EGR system; Low fuel quality; NOx sensor malfunction.
How do I fix a P21B3 diagnostic trouble code?
To fix P21B3: Check the EGR system for clogging. Diagnose the condition of the NOx adsorber. Check the exhaust tract for leaks. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with P21B3?
Limited driving only, diagnose soon
How much does it cost to fix P21B3?
The estimated repair cost for P21B3 is $56–167. Actual cost depends on your vehicle, location, and labor rates.
See also: Russian version · NationStat