P2201high severityPowertrain
NOx Sensor Circuit Range/Performance Bank 1
on 2021 Audi A4 2.0L I4 TFSI · AWD
What this code means
NOx sensor on bank 1 is responding but values are outside expected range.
Symptoms
- Check engine light
- Poor emissions performance
- Possible SCR fault codes
Common causes
- Degraded NOx sensor
- Exhaust leak near sensor
- Contaminated sensor element
Diagnostic steps
- Compare actual NOx levels to expected at various loads
- Check for exhaust leaks
- Inspect sensor condition
Repair notes
Replace NOx sensor if out of specification after leak check.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1