Elec93_Si

I have a check engine light coming on. I shorted the service connector and read a code 9. The CYU sensor. I measured the sensor and it measures right in the range of a good sensor. Has anyone had a similar problem and how was it fixed? I have already tried a new distributor after taking the advice of the local Honda mechanics. After two weeks the problem came back as soon as the weather got colder. Anyone have any ideas on what could be the problem?
Thanks