⚡ AUTO CODE FIX
🔍
EmissionsModerate✅ DIY Friendly

P0402

Exhaust Gas Recirculation Excessive Flow

Too much EGR flow detected.

SeverityModerate
CategoryEmissions
Est. Repair Cost$100–$500
Code TypePowertrain
DIY RepairYes

⚡ Common Causes

⚠️ Symptoms

✅ How to Fix — Step by Step

  • Step 1:Test EGR valve for sticking open
  • Step 2:Replace EGR solenoid
  • Step 3:Check vacuum supply
  • Step 4:Replace EGR valve
💡 Pro Tip: An EGR valve stuck open causes very rough idle and stalling — the engine acts like it has a massive vacuum leak.

Repair Cost Estimate

Full Repair Estimate
$100–$500
DIY Possible?
YES
Severity
Moderate

Frequently Asked Questions

What does OBD2 code P0402 mean?+
P0402 stands for Exhaust Gas Recirculation Excessive Flow. Too much EGR flow detected.
What causes code P0402?+
EGR valve stuck open; Faulty EGR solenoid; Incorrect EGR valve; Vacuum leak to EGR causing constant flow
How do I fix code P0402?+
Test EGR valve for sticking open; Replace EGR solenoid; Check vacuum supply; Replace EGR valve
How much does it cost to fix P0402?+
Estimated repair cost for P0402 is $100–$500.
Is P0402 DIY-friendly?+
Yes — P0402 is generally DIY-friendly with basic tools.

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