new here and think I posted this in the wrong place the first time so if you want to see full post look in the general tech section. so the short of it, bought 01 mustang gt 4.6. runs very strong. drove for 2-3 day no smoke. changed oil yesterday and now today when I leave from a stop I see a puff a smoke behind me. so im trying to figure out what pervious owner had in it to put back in till I have time to fix. thank you.