P0402: Exhaust Gas Recirculation Flow Excessive
P0402 is an OBD-II diagnostic trouble code meaning “Exhaust Gas Recirculation Flow Excessive.” The EGR system is flowing too much exhaust gas, causing rough idle or stalling. According to Au7o's database, this code appears across 86 vehicle models from 18 manufacturers. Full vehicle-specific causes and solutions at au7o.io.
Common Causes
Diagnostic Tools
To diagnose P0402, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.
Vehicles Affected by P0402
Click any vehicle to see the full issue details, symptoms, and repair guide.
Related Codes
Frequently Asked Questions
What does P0402 mean?
P0402 stands for "Exhaust Gas Recirculation Flow Excessive." The EGR system is flowing too much exhaust gas, causing rough idle or stalling.
What are the most common causes of P0402?
The most common causes of P0402 are: EGR valve stuck open, Faulty EGR pressure sensor, Vacuum leak to EGR valve, Carbon holding EGR valve open, ECU calibration issue. The specific cause varies by vehicle — Au7o documents vehicle-specific causes for 86 models.
How much does it cost to fix P0402?
Repair costs vary widely depending on the root cause and vehicle. Check the vehicle-specific issues below for estimated costs.
Which vehicles are affected by P0402?
Au7o has documented P0402 across 86 vehicle models from 18 manufacturers: Audi, BMW, Cadillac, Chrysler, Dodge, Ford, GMC, Honda, Hyundai, Jeep, Kia, Mazda, Nissan, RAM, Subaru, Toyota, Volkswagen, Volvo. See the full list below for vehicle-specific causes and repair costs.
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