Honda EGR Valve Cleaning

Here's a short DIY Video on how to clean the EGR valve on a Honda engine.

This procedure is applicable to 2.4L 4 cylinder Honda engines, found on the Civic, Accord, CR-V and Element, Acura TSX, CSX, and ILX as well as other Honda models.

The EGR valve is responsible for directing some exhaust gases back into the intake manifold to be reburned by the engine. The EGR system's purpose is to absorb some of the heat in the combustion chamber, therefore reducing the amount of harmful nitrous oxide (NOx) produced in the exhaust stream.

Because the exhaust system contains carbon, after a while the EGR valve and port can become clogged with carbon deposits. Symptoms include a laggy or unresponsive throttle, or a jerky idle or coast. It may or may not be accompanied by a P0401 Exhaust EGR Flow Insufficient engine code.

Luckily most of the time the EGR port and valve can be cleaned to restore performance. There are two 12mm nuts holding the EGR valve onto the intake manifold, and one electrical connector. To get better access, it is recommended to remove the PCV hose, vacuum line and air box tube.

Carb or throttle body cleaner and a pick can be used to clean the valve/port. This video also goes into a break down of how the EGR system works, and a physical tear down of what's inside an EGR valve.

An excellent reference video on how the EGR system works: