P0400 P0400 OBD-II: Exhaust Gas Recirculation Flow Issue
What P0400 means for you
This code indicates a moderate issue with the EGR system that can affect engine performance and emissions.
Symptoms
- The Check Engine Light will turn on
- Typically, drivers do not notice any significant issues
- However, some may experience performance issues
- Such as engine knocking during acceleration
- Particularly when the engine is under load or at higher speeds
Common causes
- The EGR (Exhaust Gas Recirculation) system is designed to lower combustion temperatures and reduce emissions.
- If the engine control module (PCM) fails to detect the expected flow from the EGR, it triggers the P0400 code.
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Send your ECUWhat this code means
The P0400 code signifies a problem with the EGR system's flow. This system recirculates a small portion of exhaust gases back into the intake manifold to limit combustion temperatures and reduce nitrogen oxide (NOx) emissions. If the PCM does not register the correct amount of EGR flow, it will set this code, indicating that the system isn't functioning as intended.
Frequently asked questions
While it may be possible to drive the vehicle, it is advisable to address the P0400 code promptly to avoid potential performance issues and increased emissions.
Repair costs for a P0400 code can vary widely, but typically range from $100 to $500 depending on the specific repairs needed for the EGR system.
Common symptoms include the illumination of the Check Engine Light and possible performance issues like engine knocking during acceleration.
