P221A

NOx Sensor 1/2 Correlation Bank 1

Severity

⚠️ Medium

Can you drive?

Yes, but get it checked soon

Approx. repair cost

$56–167 (est.)

Symptoms

Check Engine light comes on
Reduced engine power
Increased fuel consumption
Problems with passing inspection due to emissions

Causes

NOx sensor 1 or 2 malfunction
Damage to the sensor wiring harness
Problems with sensor connectors
Engine control unit malfunction
Software error in the control system

How to Fix

Check fault codes in the ECU memory
Inspect the connection and wiring harness of the NOx sensors
Check the operation of NOx sensors using diagnostic equipment
Replace faulty NOx sensor if necessary
Update ECU software if required

Related codes

P2200 P2201 P2219