P221B
NOx Sensor 1/2 Correlation Bank 2
P221B is an OBD-II diagnostic trouble code meaning: NOx Sensor 1/2 Correlation Bank 2. Common causes: nox sensor 1 or 2 fault on bank 2, damage to the wiring to the nox sensors. Estimated repair cost: $56–278.
Symptoms
- Check Engine light comes on
- Reduced engine power
- Increased fuel consumption
- Problems with passing inspection due to emissions
- Possible transition to emergency mode
Causes
- NOx sensor 1 or 2 fault on Bank 2
- Damage to the wiring to the NOx sensors
- Problems with sensor connectors
- Engine control unit malfunction
- Problems with the SCR system
How to Fix
- Check the condition of the wiring and connectors of the NOx sensors
- Read operating parameters of NOx sensors using a scanner
- Check the functionality of NOx sensors
- If necessary, replace the faulty NOx sensor
- Check the operation of the SCR system
Related codes
Error P221B by Vehicle Brand
FAQ
What does the P221B code mean?
P221B is an OBD-II diagnostic trouble code that indicates: NOx Sensor 1/2 Correlation Bank 2
What causes a P221B error code?
The most common causes of P221B include: NOx sensor 1 or 2 fault on Bank 2; Damage to the wiring to the NOx sensors; Problems with sensor connectors; Engine control unit malfunction.
How do I fix a P221B diagnostic trouble code?
To fix P221B: Check the condition of the wiring and connectors of the NOx sensors. Read operating parameters of NOx sensors using a scanner. Check the functionality of NOx sensors. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with P221B?
Yes, but get it checked soon
How much does it cost to fix P221B?
The estimated repair cost for P221B is $56–278. Actual cost depends on your vehicle, location, and labor rates.
See also: Russian version · NationStat