P0407

Q: What does OBD2 code P0407 mean?

P0407 means: Exhaust Gas Recirculation Sensor B Circuit Low. The secondary EGR position sensor (Sensor B) is reading a lower voltage than expected.

Exhaust Gas Recirculation Sensor B Circuit Low

The secondary EGR position sensor (Sensor B) is reading a lower voltage than expected.

SeverityModerate

CategoryEmissions

Est. Repair Cost$150-$350

Code TypePowertrain

DIY RepairYes

⚡ Common Causes

›Faulty EGR sensor
›Damaged wiring
›Carbon buildup affecting EGR valve position

⚠️ Symptoms

›Check engine light
›Possible rough idle
›Reduced fuel economy

✅ How to Fix — Step by Step

Step 1:Clean EGR valve and passages
Step 2:Inspect sensor wiring
Step 3:Test sensor voltage
Step 4:Replace sensor if faulty

🔧 Diagnostic Tools Required

✔OBD-II Diagnostic Scanner
✔Digital Multimeter
✔Basic Hand Tools
✔Flashlight
✔Vehicle Service Manual

Using the correct diagnostic tools helps identify the root cause of P0407 before replacing parts unnecessarily. Always confirm the fault using live data and manufacturer-recommended diagnostic procedures.

💡 Pro Tip: EGR valves get clogged with carbon over time - a thorough cleaning often resolves both flow and sensor-related EGR codes.

Repair Cost Estimate

Full Repair Estimate

$150-$350

DIY Possible?

YES

Severity

Moderate

Frequently Asked Questions

What does OBD2 code P0407 mean?+

P0407 stands for Exhaust Gas Recirculation Sensor B Circuit Low. The secondary EGR position sensor (Sensor B) is reading a lower voltage than expected.

What causes code P0407?+

Faulty EGR sensor; Damaged wiring; Carbon buildup affecting EGR valve position

How do I fix code P0407?+

Clean EGR valve and passages; Inspect sensor wiring; Test sensor voltage; Replace sensor if faulty

How much does it cost to fix P0407?+

Estimated repair cost for P0407 is $150-$350.

Is P0407 DIY-friendly?+

Yes — P0407 is generally DIY-friendly with basic tools.