P2478

Exhaust Gas Temperature Out of Range Bank 1 Sensor 1

Severity

🔴 High

Can you drive?

Do not drive — repair immediately

Approx. repair cost

$28–89 (est.)

Symptoms

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

Causes

Exhaust gas temperature sensor malfunction
Damage to the wiring or sensor connector
Clogged catalytic converter
Problems with the exhaust gas recirculation (EGR) system
Engine overheating due to other faults

How to Fix

Check the exhaust gas temperature sensor and its circuit
Inspect the catalytic converter for blockages
Check the engine cooling system
Diagnose the EGR system
Replace the faulty exhaust gas temperature sensor if necessary

Related codes

P2477 P2479 P2181