Engine-Codes - Honda - P0401 1999 Honda Accord

P0401 1999 Honda Accord Code - Exhaust Gas Recirculation Insufficient Flow

- Code Popularity: 24,405 Views
- Repair Importance Level: 2/3
- Repair Difficulty Level: 2/3
Table of contents
ChatAC AutoCodes.com AI Chat

What are the Possible Causes of the DTC P0401 1999 Honda Accord?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Exhaust Gas Recirculation Valve clogged
  • Faulty Exhaust Gas Recirculation Valve
  • Exhaust Gas Recirculation Valve harness is open or shorted
  • Exhaust Gas Recirculation Valve circuit poor electrical connection
  • Exhaust gas leaks

Code Tech Notes

The problem is common in most 1999 Honda Accord. The factory released a bulletin with instructions on how to clean the intake system.
1999 Honda Accord EGR Port Clogging OBDII Code P0401

⚠ Does your Honda have Safety Recalls? → Check here

How to Fix the DTC P0401 1999 Honda Accord?

Check the 'Possible Causes' listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

Search for P0401 1999 Honda Accord Questions and Answers: Search here →

What is the Cost to Diagnose the Code?

Labor: 1.0

The cost to diagnose the P0401 1999 Honda Accord code is 1.0 hour of labor. The diagnosis time and labor rates at auto repair shops vary depending on the location, make and model of the vehicle, and even the engine type. Most auto repair shops charge between $75 and $150 per hour.

When is the Code Detected?

Low EGR flow control is detected

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)
  • Engine hesitation

What Does the P0401 1999 Honda Accord Code Mean?

The exhaust gas recirculation (EGR) system reduces oxides of nitrogen (NOx). NOx is generated by high combustion temperatures.
The EGR system lowers peak combustion temperature by recirculating inactive exhaust gas into the air/fuel mixture, thus reducing NOx emissions.
The EGR valve position sensor is built into the EGR valve and detects the amount of valve lift. The command value for the target valve lift is previously stored in the Powertrain Control Module (PCM) so that exhaust gas recirculation can be optimized according to driving conditions.
Comparing this command value with the EGR valve position sensor output signal value, the PCM controls the EGR valve to make the amount of actual valve lift equal to the command value.
If the EGR valve position sensor output signal value differs greatly from the command value in the PCM memory for a set period of time, the EGR valve or the EGR valve position sensor is considered faulty and a DTC is stored.
P0401 1999 Honda Accord Code - Exhaust Gas Recirculation Insufficient Flow

Need more Information on the Code?

Need more information on how to fix the P0401 1999 Honda Accord code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0401 1999 Honda Accord code diagnosed by a professional: Find a repair shop in your area