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OBD2 Code P1404

Time: 2026-01-22    Source: iCarsoft Technology Inc.
Fix P1404: EGR Valve Position Sensor Circuit Issue + iCarsoft CR Eagle Guide

Fix P1404: EGR Valve Position Sensor Circuit Issue With iCarsoft CR Eagle

If your check engine light glows and a scan reveals OBD2 code P1404, you’re dealing with an Exhaust Gas Recirculation (EGR) system problem that threatens emissions compliance and engine efficiency. P1404 signals “EGR Valve Position Sensor Circuit Performance”—a fault where the EGR valve’s position sensor fails to send accurate signals to the engine’s computer. Ignore it, and you’ll face rough idling, reduced power, or failed emissions tests.

But diagnosing P1404 doesn’t have to mean overpaying at the dealership. In this guide, we’ll break down P1404 in plain English: what it is, common causes, red-flag symptoms, and how the iCarsoft CR Eagle diagnostic tool simplifies troubleshooting for DIYers and mechanics. Plus, we’ll share real customer reviews, 8 FAQs, and show you how to fix P1404 at home. Let’s get your EGR system back in top shape!

iCarsoft CR Eagle Diagnosing P1404 EGR Valve Position Sensor Circuit Issue on Vehicle

What Is OBD2 Code P1404?

P1404 is a standard OBD2 diagnostic trouble code defined as “Exhaust Gas Recirculation (EGR) Valve Position Sensor Circuit Performance”. The EGR system reduces harmful nitrogen oxide (NOx) emissions by recirculating a small amount of exhaust gas back into the intake manifold. The EGR valve position sensor monitors the valve’s opening/closing angle, sending real-time data to the Engine Control Unit (ECU).

When the ECU detects erratic, out-of-range signals from the sensor (or no signal at all), it triggers P1404. This usually points to a faulty sensor, carbon-clogged EGR valve, damaged wiring, or ECU miscommunication—all issues that demand prompt attention to keep your engine running cleanly.

Top 5 Causes of P1404

1. Carbon-Clogged EGR Valve

The #1 culprit—soot and carbon buildup from exhaust gases sticks to the valve, preventing smooth movement and skewing sensor readings.

2. Faulty EGR Valve Position Sensor

Sensors wear out from heat and vibration, failing to transmit accurate position data to the ECU.

3. Damaged Wiring/Connectors

Corrosion, fraying, or loose connections between the sensor and ECU break the circuit.

4. Stuck EGR Valve

The valve gets jammed open/closed (often from carbon buildup), forcing the sensor to send abnormal signals.

5. ECU Firmware Outdated

Old software may misinterpret sensor data, triggering false P1404 codes.

Common Symptoms of P1404

Don’t ignore these warning signs—they mean P1404 is affecting your EGR system:

  • Illuminated check engine light (MIL) or emissions warning light.
  • Rough idling or engine hesitation during acceleration.
  • Reduced fuel efficiency (the engine works harder to compensate for poor exhaust recirculation).
  • Failed emissions tests (a legal requirement for registration in most regions).
  • Engine misfires (severe cases, as airflow and fuel mixture become unbalanced).

Why the iCarsoft CR Eagle Is Your Best Tool for P1404

Basic OBD scanners can read P1404, but they can’t test the EGR valve or sensor directly. The iCarsoft CR Eagle is built for deep emissions system diagnostics, giving you professional-grade tools to pinpoint and fix P1404 from home.

Key Features That Simplify P1404 Troubleshooting:

EGR System Specialization

Reads P1404 and detailed subcodes (e.g., “EGR Sensor Circuit Low Input”) to pinpoint the root cause.

Live Data Streaming

Monitors real-time EGR valve position, sensor voltage, and ECU communication to confirm sensor or valve issues.

Bidirectional Control

Tests the EGR valve by sending commands to open/close it—critical for ruling out mechanical jams vs. sensor failure.

Multi-Brand Compatibility

Works with 50+ global vehicle brands (Ford, Toyota, BMW, Mercedes-Benz, Honda, Volkswagen, and more).

Intuitive 5-Inch Touchscreen

AutoVIN identification auto-detects your vehicle’s make/model/year, and step-by-step prompts guide beginners.

Lifetime Free Updates

Stays compatible with new vehicle models and updated EGR system technology.

Pro Tip: The CR Eagle saves you money by helping you confirm if the problem is a $30 sensor or a $150 EGR valve—no guesswork required.
Shop the iCarsoft CR Eagle Now →

Real Customer Reviews: How the CR Eagle Fixed P1404

“I got P1404 on my 2017 Ford F-150 and was quoted $400 by the dealership (EGR valve replacement). Bought the iCarsoft CR Eagle, scanned it in 2 minutes, and found a carbon-clogged EGR valve. Cleaned it with $10 EGR cleaner and used the CR Eagle to clear the code—my truck runs smoother, and I saved over $380! 10/10 for DIYers.”
— Josh T., Truck Owner

“As a small garage mechanic, I need a reliable scanner for EGR issues. The CR Eagle has fixed P1404 on Toyota Corollas, BMW 3 Series, and Honda Civics. The bidirectional EGR test is a game-changer—lets me confirm if the valve is stuck without taking it apart. The touchscreen is user-friendly, and lifetime updates mean I never miss compatibility. Worth every penny!”
— Lucas M., Independent Mechanic

“I’m not mechanically savvy, but the CR Eagle made P1404 simple. The tool walked me through scanning, identifying a faulty EGR position sensor, and clearing the code after replacement. My 2018 Hyundai Tucson no longer hesitates, and I avoided a $700 shop bill. Great investment for any car owner worried about emissions!”
— Chloe K., Daily Commuter

8 FAQs About P1404 & the iCarsoft CR Eagle

1. Can I Drive With P1404?

Yes—P1404 rarely affects immediate drivability, but long-term driving risks reduced fuel efficiency or failed emissions tests. Fix it before your next registration.

2. How Much Does It Cost to Fix P1404?

Cost varies: Cleaning the EGR valve costs $10–$30; replacing a position sensor costs $30–$100; an EGR valve costs $100–$300 (parts). Dealership repairs cost $200–$800.

3. Will the CR Eagle Work With My Vehicle?

The CR Eagle covers 50+ global brands, including Asian (Toyota, Honda, Hyundai), European (BMW, Mercedes, VW), and American (Ford, GM, Chrysler) models. Check the official compatibility list for your make/model/year.

4. How Do I Use the CR Eagle to Diagnose P1404?


  1. Plug the tool into your vehicle’s OBDII port (under the dashboard).
  2. Turn on the ignition (don’t start the engine).
  3. Select “Engine System” → “Read DTCs”—the tool displays P1404 and a description.
  4. Go to “Live Data” to monitor EGR sensor voltage—erratic readings confirm the issue.


5. Can the CR Eagle Clear P1404 Permanently?

Yes! After fixing the root cause (e.g., cleaning the valve or replacing the sensor), select “Clear DTCs” to erase P1404. Test drive to confirm no reoccurrence.

6. Do I Need Mechanical Experience to Use the CR Eagle?

No—its intuitive interface, AutoVIN identification, and multilingual support (15 languages) make it beginner-friendly. Step-by-step prompts guide you through every step.

7. What If P1404 Comes Back After Clearing It?

If the code returns, the root cause (e.g., hidden wiring damage or a stuck valve) wasn’t fixed. Use the CR Eagle’s bidirectional tests to troubleshoot further.

8. Does the CR Eagle Offer Other EGR-Related Functions?

Yes—beyond P1404, it can test EGR flow rates, monitor exhaust gas temperatures, and diagnose related codes like P0401 (EGR Flow Insufficient) or P0404 (EGR Valve Position Performance).

Final Thoughts: Don’t Let P1404 Ruin Your Emissions Test

OBD2 code P1404 is a fixable issue—with the right tool. The iCarsoft CR Eagle gives you professional-grade EGR system diagnostics and repair capabilities at a DIY-friendly price, saving you time, money, and frustration.

Whether you’re a casual car owner, DIY enthusiast, or mechanic, the CR Eagle’s durability, multi-brand coverage, and lifetime updates make it a long-term investment. Fix P1404, pass emissions tests, and restore your engine’s efficiency—all with one tool.

Ready to tackle P1404 head-on? Click below to get the iCarsoft CR Eagle and keep your vehicle running cleanly!

Buy iCarsoft CR Eagle Today →

Have questions about P1404 or the CR Eagle? Drop a comment below—we’re here to help!

Disclaimer: This guide is for informational purposes only. Always consult your vehicle’s owner’s manual or a certified mechanic before major repairs. iCarsoft is not responsible for damage from improper tool use.

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