What is the solution for the Ford Focus P0400 fault?

1 Answers
DeMaya
07/30/25 1:10am
Fault code P0400 refers to the Exhaust Gas Recirculation (EGR) valve A flow. The solution is to replace the EGR valve. The following are the consequences of a damaged EGR valve: 1. When the EGR valve is damaged, it cannot control the amount of exhaust gas recirculation. Excessive exhaust gas participating in recirculation will affect the performance of the air-fuel mixture, thereby affecting the engine's power, especially during idle, low speed, light load, and cold conditions. The recirculated exhaust gas will significantly impact engine performance, leading to engine alarms. 2. A damaged EGR valve can cause the car to burn oil, resulting in severe blue smoke from the exhaust. The reason is that the EGR valve also functions as an oil-gas separator, normally only sucking exhaust gas without oil. When the EGR valve is damaged, it loses its oil-gas separation function, sucking in oil along with the gas, allowing oil to enter the intake manifold and combustion chamber, causing oil burning and severe blue smoke from the exhaust.
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