After much frustration, I think I have solved the problem.

I just cleaned the throttle body, butterfly and that oval hole inside the body. It is quite dirty and has a lot of soot stuck to it.

I think it idles a bit higher and better now. It hasn't stalled since then. The idling is around 6000 in drive and around 1000 in park both with the A/C on.

Hope this is it.