Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
The car's computer thinks too much exhaust gas is being recycled back into the engine. It's like trying to breathe in too much of your own breath.
The Exhaust Gas Recirculation (EGR) system is designed to reduce emissions by recirculating a portion of the engine's exhaust gas back to the engine cylinders. Code P0402 indicates that the EGR valve is allowing too much exhaust gas to flow back into the engine.
The EGR system helps in reducing nitrogen oxide emissions by recirculating a portion of the exhaust gases back into the engine intake. The P0402 code is triggered when the powertrain control module (PCM) detects that the EGR flow is higher than expected, which can affect engine performance and emissions.
• Check Engine Light is on
• Rough idle
• Poor fuel economy
• Faulty EGR valve
• Clogged EGR passages
• Defective EGR sensor
EGR: Exhaust Gas Recirculation
PCM: Powertrain Control Module
• Inspect the EGR valve for proper operation.
• Check for clogged EGR passages.
• Test the EGR sensor for faults.
• Replace the EGR valve if faulty.
• Clean the EGR passages.
• Replace the EGR sensor if defective.
• OBD-II scanner
• Wrench set
• Vacuum gauge
$150 - $400
Moderate
• Ford F-150
• Chevrolet Silverado
• Toyota Camry
• Regularly clean the EGR system.
• Use quality fuel to prevent carbon buildup.
• Perform regular engine maintenance.
Engine Performance
• Avoid driving the vehicle until repaired to prevent further damage.
• Consult a professional mechanic for accurate diagnosis.
Check with the vehicle manufacturer for warranty coverage on emissions-related components.
The P0402 code has been a common issue since the introduction of EGR systems in vehicles to meet emission standards.
Moderate – Address the issue soon to avoid potential engine damage and increased emissions.
Driving with a malfunctioning EGR system can lead to increased emissions, which may violate local emissions laws.
• Engine at normal operating temperature
• Vehicle at idle or low speed
The EGR valve is typically located on the engine intake manifold or near the throttle body.
Q: What happens if I ignore the P0402 code?
A: Ignoring the code can lead to poor engine performance and increased emissions, potentially causing damage to the engine over time.
Q: Can I drive with a P0402 code?
A: While the vehicle may still be drivable, it is not recommended to ignore the issue as it can lead to further engine problems.
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