P21B5

NOx Adsorber - Over Temperature Bank 2

Severity

🔴 High

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$167–556 (est.)

Symptoms

Check Engine light comes on
Reduced engine power
Increased fuel consumption
Unusual odors from the exhaust system
Dips during acceleration

Causes

NOx canister temperature sensor malfunction
Problems with the adsorber regeneration system
Exhaust system clogged
Engine control fault
Mechanical damage to the NOx adsorber

How to Fix

Check the readings of the NOx adsorber temperature sensor
Diagnose the adsorber regeneration system
Check the exhaust system for blockages
Scan the engine ECU for related errors
If necessary, replace the NOx adsorber

Related codes

P21B4 P21B6 P21B7