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P0404 on Toyota 4Runner

Exhaust Gas Recirculation (EGR) Circuit Range/Performance

Factory diagnostic protocol and troubleshooting wire for fault code P0404 specifically for the Toyota 4Runner (2020–2026, 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl).

Verified OEM Telemetry & Field Repair Tree
Toyota 4Runner2020–2026
Toyota 4Runner
SUV4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
4Runner SAE Mode $01
ECU Network Bus
500 kbps CAN-FD
ISO 15765-4 Compliant
Drivability Status
Not Recommended
Medium urgency level
Est. Repair Cost
$150 - $400 (DIY: $60 - $180)
Parts & Labor DIY
Check P0404 On Another Toyota Model:
Diagnose P0404 on Specific 4Runner Model Year:

1. Symptoms of P0404 on Toyota 4Runner

When the Engine Control Module (ECM/PCM) on your Toyota 4Runner (4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl) logs fault code P0404, drivers commonly observe:

Check Engine Light on on Toyota 4Runner (4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl)
Intermittent rough idle on Toyota 4Runner (4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl)
Slight hesitation when cruising on Toyota 4Runner (4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl)
Failed emissions test on Toyota 4Runner (4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl)
Toyota 4Runner OBD-II Port Location
The 16-pin diagnostic connector is located Lower dashboard near parking brake mechanism. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Toyota 4Runner

Historical warranty claims and technical repair bulletins for Toyota 4Runner point to the following failure distribution:

55%
Carbon deposits restricting linear EGR pintle movement (Toyota OEM Part)
25%
Worn internal EGR position feedback potentiometer (Toyota OEM Part)
12%
Wiring harness resistance or corroded connector pin (Toyota OEM Part)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for Toyota 4Runner.

3. Step-by-Step DIY Repair Guide for Toyota 4Runner

01
Check EGR Position PID on Scanner

Compare commanded EGR percentage vs actual position voltage. on the Toyota 4Runner equipped with 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl.

Required Tool: OBD-II Scanner
02
Clean EGR Pintle and Housing

Clean carbon buildup restricting valve stroke. on the Toyota 4Runner equipped with 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl.

Required Tool: Carb Cleaner, Wire Brush
03
Replace Electronic EGR Valve

If potentiometer is worn out, install new OEM electronic EGR valve. on the Toyota 4Runner equipped with 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl.

Required Tool: Socket Set, New Gasket
04
Clear Codes and Road Test

Clear DTCs and complete an EGR monitor drive cycle. on the Toyota 4Runner equipped with 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl.

Required Tool: OBD-II Scanner
Recommended Parts & Testing Tools

Equipment for Diagnosing Toyota 4Runner (P0404)

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Direct-Fit Replacement Part

Toyota 4Runner OEM Replacement Sensor

4.7 / 5.0 (Verified Fit)

Direct-fit replacement assembly engineered to OEM tolerances for Toyota 4Runner.

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Sensor Signal Voltage Meter

AstroAI Auto-Ranging Digital Multimeter

4.6 / 5.0 (Best Seller)

Essential for testing 0.1V–5.0V sensor reference signals, ground continuity (<0.20Ω), and harness resistance.

$29.99 Prime
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Top Mobile OBD-II Scanner

BlueDriver Bluetooth Pro OBDII Scan Tool

4.7 / 5.0 (50,000+ Reviews)

Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.

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Other Common Fault Codes on Toyota 4Runner

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Toyota 4Runner:

4. Toyota 4Runner P0404 FAQs

What causes code P0404 to trigger on a Toyota 4Runner?

On the Toyota 4Runner (4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl), P0404 is most frequently caused by Carbon deposits restricting linear EGR pintle movement or Worn internal EGR position feedback potentiometer.

Where is the OBD-II port located on my Toyota 4Runner?

On the Toyota 4Runner, the 16-pin DLC diagnostic connector is located Lower dashboard near parking brake mechanism. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my Toyota 4Runner with code P0404?

Yes. Normal drivability is maintained in most conditions. Given that P0404 carries a Medium severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.