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P0666

Overview

Code

P0666

Code Type

P

Code Class

P0

System

Engine

Severity Level

High

Emissions Related

true

Drivability Impact

Major

Diagnostic Protocol

OBD2

Freeze Frame Useful

true

Code Definition

Diagnostic trouble code P0666 indicates a malfunction in the exhaust gas recirculation (EGR) valve sensor circuit

Symptoms

Engine misfire Poor acceleration

Overview applies to this diagnostic code.

Affected Systems

On This Page

  • Code Definition

  • Symptoms

  • Affected Systems

  • Possible Causes

  • Diagnostic Steps

  • Drive Safety Notes​

More Resources

Exhaust gas recirculation (EGR) valve

Possible Causes

Faulty EGR valve Wiring issues

Diagnostic Steps

1 Inspect EGR valve sensor 2 Test sensor output

Drive Safety Notes

EGR issues can increase emissions and reduce performance

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