P049CEGR B Flow Excessive Detected
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- Exhaust gas recirculation (EGR) routes part of the exhaust back into the intake to lower combustion temperature and NOx. Circuit B is the second EGR path; on diesels with two circuits it is the low-pressure EGR, which takes exhaust after the particulate filter and feeds it in before the turbo compressor (GM diesels 2016–18, FCA's 2.2 and 3.0 diesels). P049C means too much flow in circuit B – fresh air mass drops further than modelled, or EGR flows with the low-pressure valve closed; CARB explicitly requires a leaking valve to be detected. No manufacturer document available to us uses P049C; the closest is FCA's P045E for a low-pressure valve stuck open. Smoke, lack of power and rough idle follow, and low-pressure EGR is switched off.
- What you may notice
- Check engine light on
- Lack of power, black smoke
- Rough idle or misfire, in extreme cases stalling
- Likely causes
- LikelyLow-pressure EGR valve stuck open or not sealing (soot)
- PossiblePosition sensor B implausible (valve seemingly closed)
- RareLeak between exhaust side and intake
- RareAir mass meter reading too low
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €150 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.