P04DE
Cold Start EGR A Flow Excessive Detected
Same as P04DD with EGR flow above the cold-start target - typically valve sticking open during the cold phase or position sensor offset low.
- 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.
- EGR valve A sticking open when coldCommon
Parts involved
- EGR Valve A
- EGR Position Sensor A
P04DE 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.