Yes, you must always show kibud av v’em, except in response to a specific request to do something against halacha. After refusing to do what they wanted, you must still show them kibud for other things. Parents are in a special category. They gave us our lives. By the way, the halacha is to honor them, but it actually says nothing about LOVING them, as contrasted with the Shema, in which we are commanded to love Hashem with all our hearts, souls, and capabilities.