I was wondering if I should replace my egr valve? I had a p0404 code so I took the valve off and cleaned it with TB cleaner. Replaced the egr valve gasket and reinstalled it on my honda. Cleared the code drove for 10 mins and the code came back.P0404.I was told I should replace the egr valve.I don't think the egr passages are clogged because that would threw a Code: P0401 Insufficient EGR Flowcode and I never did get that code.
The car runs great. No hesitation at all.I would have never knew there was a problem if the check engine light didn't come on.
If you are going to chemically clean teh egr use a decarbonizer. All auto dealers should have it, ford and gm use the same stuff it take a little bit for it to soak then drive it see if that cures it if not then a new egr