P1400Auxiliary Emission Controls

Cold Start Emission Reduction Control System (varies by make)

P1400 is a manufacturer-specific code. On Honda/Acura it relates to the EGR valve position, and on some makes it references a cold-start emission control or EGR circuit. Always confirm the make-specific definition.

🚗 Yes in most cases; it is usually an emissions-related fault.

LOW

severity

🎯 Top Causes, Ranked by Likelihood

#1EGR valve or position sensor fault$100-$400

45%

A stuck EGR valve or bad position sensor sets the code (Honda).

#2EGR passage or vacuum control fault$50-$300

30%

Blocked passages or vacuum problems affect EGR operation.

#3Wiring or connector fault$50-$250

25%

An open or shorted EGR circuit triggers the code.

🩺 Common Symptoms

Check engine light
Rough idle or hesitation
Possible pinging under load
Failed emissions test

💰 Repair Cost: DIY vs Shop

DIY Cost

$50-$400

Shop Cost

$150-$500

📋 Free OBD2 Code Cheat Sheet

The 50 most common codes with likely cause and DIY fix cost. Sent once, no spam.

🔧 How to Diagnose P1400

1Confirm the make-specific definition for P1400

2Inspect and clean the EGR valve and passages

3Test the EGR position sensor and wiring

4Replace faulty EGR components as needed

❓ Frequently Asked Questions

Can I drive with P1400?

Usually yes short-term, but it is emissions related and can cause pinging or rough idle.

What does P1400 mean?

It is a make-specific code often tied to EGR position (Honda) or cold-start emission control; confirm your vehicle's definition.

What causes P1400?

A faulty EGR valve, position sensor, blocked passages, or wiring issues are common causes.

🔗 Related Codes

P0401P0404P0405