P04DECold Start EGR A 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. P04DE is the counterpart of P04DD: during an active cold-start strategy the flow of EGR A is too high – the strategy calls for little or limited EGR, but the valve lets more through. CARB requires separate codes for cold-start faults. No manufacturer document available to us uses P04DE; FCA uses the neighbouring code P04DD, so its use there is plausible but not documented. Too much exhaust in a cold engine causes rough running, smoke and in extreme cases stalling.
- What you may notice
- Check engine light on
- Rough idle after a cold start
- Smoke or soot after a cold start (diesel), stalling possible
- Likely causes
- LikelyEGR valve not closing fully (soot, condensate, stuck open)
- PossiblePosition sensor reports a wrong position
- RareAir mass or pressure difference misreading
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €150 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.