Had emergency appendix out that ruptured, now I have a convent bad taste in mouth and hard left side around wound after 4 months?

Maybe a hernia. Not sure about the bad taste, but the the hard lump under the wound could represent a hernia, where the abdominal contents are coming through a hole in the abdominal muscles. Even though they were closed, anywhere from 5-20% will open back up depending on many factors such as infection, obesity, genetics, and even suturing technique. See your surgeon for an exam soon to find out. Hope this helps!