ezOBD2 - Free OBD2 Code Lookup and Check Engine Light Diagnostic Tool

Find Your OBD2 Code Fast

Type the code from your scanner to get causes, symptoms, and fixes.

Code P0407

Quick reference

P0407 at a glance

Plain-language meaning
Your car has a system that helps reduce pollution, and it's not working right because one of its sensors isn't getting enough power.
Urgency
Moderate – Addressing this issue promptly can prevent further engine performance problems.
Difficulty
Moderate
System
Sensor Issue
Tools mentioned
OBD-II scanner, Multimeter, Socket set

This summary uses the existing diagnostic information shown in full below.

Laymans terms

Your car has a system that helps reduce pollution, and it's not working right because one of its sensors isn't getting enough power.

Explanation

The EGR (Exhaust Gas Recirculation) system helps reduce emissions by recirculating a portion of the exhaust gases back into the engine cylinders. The EGR Sensor B monitors the position of the EGR valve. A 'Circuit Low' code indicates that the sensor is reading a voltage lower than the expected range.

Technical description

The P0407 code is triggered when the Engine Control Module (ECM) detects that the EGR Sensor B circuit is reporting a voltage that is lower than the specified threshold. This could be due to a faulty sensor, wiring issues, or a problem with the EGR valve itself.

Symptoms

• Check Engine Light is on

• Poor engine performance

• Increased emissions

Common Causes

• Faulty EGR position sensor

• Wiring issues or poor electrical connections

• Faulty EGR valve

Glossary

EGR: Exhaust Gas Recirculation

ECM: Engine Control Module

Diagnosis steps

• Use an OBD-II scanner to confirm the code.

• Inspect the wiring and connections to the EGR sensor.

• Test the EGR sensor for proper voltage output.

Repair procedures

• Repair or replace damaged wiring or connectors.

• Replace the EGR position sensor.

• Replace the EGR valve if necessary.

Tools required

• OBD-II scanner

• Multimeter

• Socket set

Estimated repair cost

$100 - $300

Difficulty level

Moderate

Commonly affected vehicles

• Ford F-150

• Chevrolet Silverado

• Toyota Camry

Preventive measures

• Regularly inspect and clean the EGR valve.

• Ensure all electrical connections are secure.

• Use quality fuel to reduce carbon buildup.

Error code type

Sensor Issue

User experience recommendations

• Have the vehicle inspected by a professional if you're unsure.

• Avoid driving for long periods if the Check Engine Light is on.

Warranty information

Check your vehicle's warranty for coverage on emissions-related components.

Historical data

The P0407 code has been a common issue in vehicles with EGR systems, particularly in models from the early 2000s.

Urgency level

Moderate – Addressing this issue promptly can prevent further engine performance problems.

Testing conditions

• Engine at operating temperature

• Idle and under load conditions

Component location

The EGR sensor is typically located near the EGR valve, which is mounted on or near the intake manifold.

FAQs

Q: Can I drive my car with a P0407 code?
A: While you may be able to drive the car, it's best to fix the issue soon to avoid increased emissions and potential engine performance problems.

Q: How can I clear a P0407 code?
A: After repairing the issue, you can clear the code with an OBD-II scanner. If the problem persists, the code will return.

Optional diagnostic gear

Tools that may help diagnose P0407

THINKCAR ThinkScan Bidirectional diagnostic tool illustration

High-End · Full-system diagnostics

THINKCAR ThinkScan Bidirectional

A full-system bidirectional platform aimed at advanced DIY users and professional diagnostic workflows.

Network faults often require full-system access instead of a generic code reader alone.

View on Amazon
Klein Tools MM325 diagnostic tool illustration

Universal · Digital multimeter

Klein Tools MM325

A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.

Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.

View on Amazon
WORKPRO Wiring Repair Kit diagnostic tool illustration

Universal · Wire connectors and repair kit

WORKPRO Wiring Repair Kit

Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.

Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.

View on Amazon

These are optional diagnostic tools, not guaranteed fixes. As an Amazon Associate I earn from qualifying purchases.

Source: ezOBD2 diagnostic database
🌙