Subaru SVX stalling issues

Hi, I have an SVX that is suffering at the moment with stalling issues. Sometimes it’s fine then it will start cutting out while driving along and won’t tick over either when in neutral or park! The mechanic I normally use has changed the maf sensor and plugs and various vacuum pipes which helped a little bit but ultimately the problem is still there! Has anyone experienced similar problems with one of these? Or can someone recommend a garage that could diagnose and fix the issue? Thank you.