EGR B Flow Insufficient Detected
Same as P049A but specifically with measured flow below the required rate - typically EGR valve sticking closed or cooler heavily clogged.
Affected components
- Egr valve b
- Egr cooler b
Common causes
- High likelihood: EGR valve B sticking closed
- Medium likelihood: EGR cooler B heavily clogged with soot
Possible symptoms
- Check engine light on
- Pinging or knocking under load
- Power loss and hesitation
- Possible rough idle
- Failed emissions inspection (NOx)
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.