P0402 P0402 OBD-II: Excessive Exhaust Gas Recirculation Detected
What P0402 means for you
The code indicates a moderate issue with the EGR system that may affect vehicle performance.
Symptoms
- The Check Engine Light will turn on.
- Typically, drivers may not notice any significant issues.
- However, some drivers may experience performance issues.
- These issues can include stalling at stop signs, rough idling, hesitation, misfires, or reduced power during acceleration.
- There may also be a noticeable drop in fuel efficiency.
Common causes
- The EGR (Exhaust Gas Recirculation) system is designed to lower combustion temperatures and minimize emissions.
- If the engine control module (PCM) fails to recognize the expected flow from the EGR system, it triggers code P0402.
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Send your ECUWhat this code means
Code P0402 indicates that the vehicle's EGR system is allowing an excessive amount of exhaust gases to re-enter the combustion chamber. This can occur when the EGR valve is malfunctioning or if there are issues within the EGR system itself, leading to improper flow rates.
How a workshop diagnoses it
1. Use a scan tool to retrieve the trouble code and document freeze frame data. 2. Inspect the EGR valve and associated components for blockages or damage. 3. Check the DPFE (Differential Pressure Feedback EGR) or EVP (EGR Valve Position) sensors for proper operation. 4. Test the EGR system under conditions that replicate the code setting to monitor its performance.
Frequently asked questions
It is not advisable to continue driving with a P0402 code, as it may lead to performance issues and increased emissions.
Repair costs for a P0402 code can vary widely, typically ranging from $100 to $500, depending on the specific repairs needed.
Common symptoms include the Check Engine Light being on, potential stalling, rough idling, and reduced fuel economy.
A P0402 code is triggered when the PCM detects excessive flow from the EGR system, which can be due to a malfunctioning EGR valve or related components.
Ignoring a P0402 code is not safe, as it can lead to more serious engine issues and increased emissions over time.
