If this is a repeat post, I apologise. My last seems to have disappeared.
I love hummus and have used peanut butter as a substitute for tahini, but it seemed to be missing something. I keep a bottle of dark sesame oil around for seasoning, so I added some, starting with just a few drops, until it tasted right to me. I suggest doing it this way because I find that some sesame oils are stronger than others.
AnneR