My 99 Honda Prelude vtec type sh is throwing PO401, PO1491 egr codes. I had the egr valve and the egr control solenoid valve replaced already and I had the vacuum lines cleaned with carb cleaner. Checked both vacuum lines and they had vacuum and voltage looks good too. Yesterday I was driving and the Check engine and ATTS lights came back on. Any suggestions?

 

Could be the actual EGR ports in the intake manifold. I'm a '97 SH w/ 141k and currently having the same problem. I'm hoping to pull my IM in the next week or two and give it all a good cleaning. Somebody did a write-up on here about how to actual clean the EGR ports (requires drilling out plugs on the IM, cleaning and installing new plugs) which is what my local Honda dealership also said they do for that. Helm's manual says you can just clean it with carb cleaner though, so that's what I'm going to try first.

 

I just wanted to post a reply to my egr problems. After replacing the erg solenoid valve and the erg valve and the check engine light and the ATTS light were still on. I decided to have the erg ports in the im cleaned out and that worked. Only one was clogged so I guess it only takes one to throw a code, but it is all good now.

 

Did you do it your self or have the dealer do it?

 

I took my car to this guy that works on Hondas and Acuras by my house. He said it took him about an hour and charged me $60. He also threaded the ports with screws so if they get clogged again they will be easy to remove and clean.

 

I was having the same issue with my 2000 SH with 112k miles (EGR flow insufficient). I read the posting for a EGR port cleaning DIY on PreludePower.com - http://www.preludepower.com/fo...75440 . I went to the dealership and bought the replacement plugs .30 ea. I wanted to do it myself, but was lazy since it has been very cold. I also considered using SeaFoam through the brake booster vacuum line to clean (hopefully) the ERG ports out. When I went to Advance Auto to buy an oil filter wrench, I saw Shell V-Power Fuel System Cleaner (a new product) and I bought a bottle. I poured it into the tank when I filled up with Shell SU2000, and after one and a half tanks of Shell SU2000 and mostly hwy driving, my CEL has gone away! I still might use GM top engine cleaner, SeaFoam, or do the EGR port cleaning, but for now I am going to hold off until the CEL comes on again.


Modified by TheJGB3 at 10:55 PM 4/2/2008