This just started happening a few days ago,since then I've replaced the usual culprits, such as, upstream o2, iacv, map, tps. It's got an idle surge between 1200-2000 rpm and after a drive it will surge only and 1500 rpm and sound like a brideported rx7, and can't think of what it could be, the only thing I haven't tried is bleeding the coolant, which I'll do this Wednesday when I have time