P23B4

NOx Sensor Heater Sense Circuit Bank 1 Sensor 3

Severity

⚠️ Medium

Can you drive?

Yes, but get it checked soon

Approx. repair cost

$56–167 (est.)

Symptoms

Check Engine Light Is On
Reduced engine power
Increased fuel consumption
Dips during acceleration
Unstable engine idling

Causes

NOx sensor malfunction
Open or short circuit in heating circuit
Poor contact in the sensor connector
Wiring harness damage
Engine control unit malfunction

How to Fix

Check the continuity of the NOx sensor heating circuit
Inspect connectors and wires for damage
Check the resistance of the sensor heating element
If necessary, replace the NOx sensor
Reset the error code and check if it returns

Related codes

P23B5 P23B6 P23B7