In reply to ss I changed my o2 sensor it lasts about six months and sets a code 43 some how I know I am getting a rich condition on this 1992 honda accord.The vacuum is right onthe money 21 inches of mercury. I did a compression test today and all cylinders registered 180 compression.The only thing left to check is the injectors. they cchecked electrically okay I have the helm manual which would probably eliminate a lot of posts by people if they had it.