Hey everyone, just bought back my first car. It’s a 2004 mustang 3.8 5speed. The owner I sold it to just rebuilt the transmission back in June and just swapped in a new motor w 80k miles last week. The car has a few strange issues though, the first was a random misfire on startup (first 1000 revolutions) and a misfire in cylinders 1,2,4. These were pending codes that went away after I fixed a vacuum leak coming from the upper intake plenum going to the cold air intake. Now, these codes are gone... however, after about 2 mins on a cold start there is a trumpet like noise that sounds like it’s coming from either the intake or upper intake plenum. (The sound starts as soon as the car finishes it’s “initial” warmup). The sound disappears when under moderate throttle (while driving) but as soon as you let off, it comes right back. Also, the car cuts out at higher Rpms or when you mash the throttle. Any suggestions? Thx