P049C
EGR B Flow Excessive Detected
Same as P049A but with measured flow above the required rate - typically EGR valve sticking open 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 B sticking openCommon
- Position sensor reads lowPossible
Parts involved
- EGR Valve B
- EGR Position Sensor B
P049C 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.