I have owned this project since May. It came with a burned out CEL. There were 2 codes: p0440 EVAP(3-1-5) and the terrible long term fuel trim code. Well, the PO also must have known as all of the vacuum elbows were new. I cleared the codes and forgot about them. The fuel mileage was not as good as I expected and what vacuum pressure?

After cleaning up the PCV system and the PTC along with the EGR valve, the vacuum got better, but still not as strong as I liked.

Today, I was in a very long and slow line at Goodwill. After about 15 minutes, the idle changed ever so slightly and the CEL came on! I drove home and learned that it was the EVAP code. While reading about the 3-1-5 error online, it made sense to me that the purge valve finally died. When that happens, the purge valve stays open, the vacuum decreases slightly in the manifold, the mixture is richer due to the draw from the charcoal manifold, and that messes up the long term fuel mixture.

I will test the purge valve this weekend to see if it is open with a cold engine and order a new purge valve. Heck, it is only 20 years old!

Then I will probably sell the project, I ran out of garage space.
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Keeping it running is better than buying new