Is there a mitzvah of cibud av ve am after one of that parents die? Is going to a levaya/kevura a mitzvah of cibud av ve'am (or any other mitzvah?)
ariel dvash,
Kibud Av v'Em applies even after death (Kidushin here, and Shulchan Aruch, Yoreh Deah 240:9).
Buriel and participation in the funeral are a Mitzvah; see Yoreh Deah 343 and 361. The Chafetz Chayim in his Ahavas Chesed (section 3, chapter 5) explains at length concerning the Chesed involved.
All the best,
Reuven Weiner