By Samuel The P1399 code indicates a malfunction in the Exhaust Gas Recirculation (EGR) system, resulting in increased pollution and poor engine performance.
Symptoms of this code include poorer fuel efficiency, hesitation when accelerating, strange engine noises, and rough idling.
The problem can be caused by a faulty EGR valve, sensors, or solenoid, or even carbon buildup in the engine's combustion chamber.
To fix the issue, the root cause needs to be identified and the faulty component replaced to get the engine running smoothly again.
What does this Code Mean
When your Chevrolet's onboard computer shows the P1399 code, it means there's a problem with the exhaust gas recirculation (EGR) system.
This system helps reduce pollution by reusing some of the engine's exhaust gas.
The P1399 code means the EGR system isn't working right, which can cause more pollution and make the engine run poorly.
You need to have the EGR system checked to find the problem.
This may involve checking the EGR valve, vacuum hoses, and sensors to see if they're broken or clogged.
What are the Symptoms
Your Chevrolet's faulty EGR system causes problems you'll notice while driving.
These problems include:
- The engine light comes on in the dashboard, showing there's an issue.
- You'll get poorer fuel efficiency, which means higher fuel costs.
- The engine may hesitate when you accelerate, making it hard to merge or go up hills.
- You might hear strange noises, like knocking or pinging, from the engine.
- In some cases, the engine might idle rough or stall when you're stopped at a light or in traffic.
What are the Causes
The faulty EGR system in your Chevrolet is caused by several factors.
- A clogged or dirty EGR valve prevents proper exhaust gas recirculation.
- Faulty EGR temperature sensors send incorrect signals to the engine control module, causing the P1399 code.
- A malfunctioning EGR solenoid disrupts the flow of exhaust gases, leading to the error.
- Improperly installed or damaged EGR system components trigger the code.
- Carbon buildup in the engine's combustion chamber increases NOx emissions, prompting the P1399 code.
What Tools are Needed to Diagnose
To diagnose the P1399 code on your Chevrolet, you need certain tools.
You need:
- A code reader or scan tool to get the trouble code and freeze frame data
- A multimeter to test electrical circuits and components
- A wiring diagram to trace the circuits related to the code
- A vacuum gauge to test intake manifold vacuum
- A fuel pressure gauge to test fuel system pressure
How to fix Step by Step
Step 1: Locate the faulty Exhaust Gas Recirculation (EGR) system valve and remove it.
Step 2: Inspect the valve for any blockages or carbon buildup.
Clean or replace the valve as needed.
Step 3: Reconnect the valve and clear the P1399 code using your scan tool.
Step 4: Restart the engine and check for any leaks in the EGR system.
Step 5: If the code persists, replace the EGR pressure sensor or the engine control module, and double-check your work to ensure the repair is complete and the code is cleared.
What are the Common Diagnosis Mistakes
Common diagnosis mistakes can lead to incomplete or incorrect repairs.
These mistakes include:
- Not re-scanning the system after clearing the code to verify the repair
- Not checking for other related trouble codes
- Ignoring other symptoms or warning lights related to the issue
- Not thoroughly testing the system to ensure the repair is complete
- Relying only on a code reader or scanner without doing physical inspections or tests
What is the Repair Cost
The P1399 Chevrolet repair cost varies widely, ranging from $150 to $300 for a faulty oxygen sensor.
To $1,000 to $2,000 or more for a malfunctioning catalytic converter, and up to $3,000 for replacing the entire exhaust system.
Can I drive safely with this code?
You can drive safely with a P1399 code if the check engine light is steady, but get it checked and repaired soon to avoid decreased fuel efficiency, reduced performance, and increased emissions.