Code result
P040F
EGR Temperature Sensor A/B Correlation
Moderate severity
What it means
EGR temperature sensors A and B disagree by more than the allowed tolerance over a drive cycle. EGR mixes inert exhaust into intake to lower combustion peak temperature — too little raises NOx, too much causes misfires and rough running.
Is it safe to drive?
Use caution
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
One sensor drifts
highOne of the most commonly reported causes for this code — check this first.
Related help
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