Porsche EGR Valve & EGR System Fault Codes — Causes, Symptoms & Repair

Browse 17 egr valve & egr system fault codes relevant to Porsche vehicles. A fault code identifies the system reporting an out-of-range condition; accurate repair starts with a full diagnostic scan and live-data checks, not a parts guess.

Common Porsche EGR Valve & EGR System Fault Codes

• P0400 — EGR Flow Malfunction
• P0401 — EGR Insufficient Flow
• P0402 — EGR Excessive Flow
• P0403 — EGR Solenoid Circuit
• P0404 — EGR Range/Performance
• P0405 — EGR Position Sensor Low
• P0406 — EGR Position Sensor High
• P0408 — EGR Sensor B Circuit High
• P040C — EGR Temperature Sensor Performance
• P2457 — EGR Cooler Performance
• P0407 — EGR Position Sensor B Low
• P0409 — EGR Sensor A Circuit
• P0410 — Secondary Air Injection System Malfunction
• P0411 — Secondary Air Injection Incorrect Flow
• P20E8 — Reductant Injection Low — NOx Reduction
• P205B — Reductant Tank Heater Circuit
• P2BAD — NOx Emission Mass Flow Too High

What to Do When a Warning Light Appears

• Record the warning message and any change in how the car drives.
• Avoid long or high-load driving if the warning is flashing, the car is overheating, or it has entered limp mode.
• Book a diagnostic scan so the stored code, live data and root cause can be checked before parts are replaced.