P04CF
EGR Temperature Sensor C Circuit Range or Performance
Same as P04CE with the signal in plausible range yet not matching the engine model - typically sensor drift or a slow response after engine warm-up.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Symptoms
- Check engine light on
- Pinging or knocking under load
- Power loss and hesitation
- Possible rough idle
- Failed emissions inspection (NOx)
Common causes
Ordered by how often each turns out to be the cause.
- Sensor element driftedCommon
Parts involved
- EGR Temperature Sensor C
P04CF is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.