P0401 EGR Valve Port Cleaning

This is my DIY for clearing the CEL code P0401 (EGR Insufficient Flow) on a 98 Honda Prelude.

In cars with OBD2 if the EGR valve is restricted by carbon deposits it will detect that and throw a CEL. To get rid of that CEL you must clean out the carbon to allow flow.

After combustion occurs within the engine it creates exhaust. Gas from the exhaust straight from the engine is very bad for the air. The EGR valve recaptures that exhaust and runs it through the combustion process again, which lowers the temperature of the fumes (exhaust gas) and lowers the amount of pollution exiting into the atmosphere.

If you don't fix it you won't pass SMOG in California. You may experience rough idling and poor acceleration.

Tips:

Get your "EGR port plugs" from Honda. They will have it.
Removing the injectors are important to allow clearance to the port plugs.
When you pull out the injectors you might as well clean them since they are out.
Slide hammers make pulling the port plugs out easily.
Drill with a bit the size of your tap. Drilling halfway through the port plug to should be enough distance to fully grab the port with the slide hammer.
If after you clean your ports and valve the CEL has not been cleared, you EGR valve maybe faulty and needs to be replaced.

Category:

Autos & Vehicles

Tags:

• P0401
• Honda
• EGR
• Prelude
• cars
• Exhaust
• Recirculation
• Engines
• Valve
• Gas
• vehicle
• emissions
• testing
• replacement
• ports
• cleanup
• cleaning
• Toyota
• Ford
• GM
• Accord
• Civic
• check
• CEL
• code
• DIY
• How
• passages
• Port
• Plugs
• engine
• motorcycle
• start
• pollution
• carbon
• OBD2

[TheFrhen]

you change the egr valve? where u bought it at?

[napafitpro]

@TheFrhen I didn't change the EGR Valve. I just cleaned it.

[frankyjoseph91]

how the F did you get the second bolt off the egr? the one most near the IM.

I used a wrench to get the one near the head off but I cant get the other and im stripping it :/

[napafitpro]

@frankyjoseph91 use a long extension. at least 6 inches. if u dont have a long one, attach an extension to another extension...

[LeilaP700]

do you need the air pressure gun?

[napafitpro]

@LeilaP700 no

[916smog]

Pretty good video. A+

[bertdiaz35]

Why did you drill out the ports for?...that was a little fast for me. Could you explain that a little more?

[OVERKILL173]

wtf why am i watching this and how did i get hear lol i own a nissan frontier

[yamaraptor250]

nice gloves lol



[apyer918]

do you have to tap new holes?



[TheFrhen]

i clean twice mine and it keep trowing cel p0401, for about ten months i keep using it like that and then i did a troubleshoot one day, then i found out that the vacuum solenoid goes out. so now its good save me $250 :)

[chemesgh]

Did you have to do anything special to access and remove the bolt closest to the fire wall? I tried using a crows foot because I couldn't get a socket in there, rounded it off. :/

[emijun1983]

I did it and now idle is so smooth. Thanks great video!!!

[mybrotherkeeper]

What did you drill the plugs out for...that was a little fast for me. Could you explain that a little more?