P225D

NOx Sensor Performance - Signal Biased/Stuck Low Bank 1 Sensor 1

Severity

⚠️ Medium

Can you drive?

Yes, but get it checked soon

Approx. repair cost

$167–389 (est.)

Symptoms

Check Engine light comes on
Reduced engine power
Increased fuel consumption
Unstable engine idling
Increased level of harmful emissions

Causes

Faulty NOx Bank 1 Sensor 1
Damaged NOx sensor wiring harness
Poor contact in NOx sensor connector
Software error in the engine control module (ECU)
Problems with the Exhaust Gas Recirculation (EGR) system

How to Fix

Check the condition of the NOx sensor connectors and wiring harness
Check NOx sensor readings using diagnostic equipment
Replace NOx Bank 1 Sensor 1 if necessary
Clean the exhaust gas recirculation (EGR) system if necessary
Update engine ECU software

Related codes

P225E P2200 P2201