How can one honor his parents after their death, and is the son's memorization of the Quran sufficient to compensate for his shortcomings in honoring his father during his lifetime?

Whoever has fallen short in honoring their parents can make amends after their passing if their intention is sincere and they repent with a genuine repentance. This can be done by:

1. Praying for them (supplicating for them).

2. Seeking forgiveness for them.

3. Fulfilling their promises/covenants.

4. Maintaining ties of kinship that are only connected through them.

5. Honoring their friends.

6. Giving charity on their behalf, as the deceased benefits from it.

7. Every good deed one performs and dedicates its reward to their parents, such as reciting and reflecting upon the Quran.