99 Cobra Chugging In Low Gears

[Detroit Stang]

My 99 Cobra chugs pretty good in lower gears when I'm off the gas. Specifically in 1st and 2nd. 3rd isn't too bad. When I'm on the gas, it runs pretty good. It has never thrown a code, and seems to drive well otherwise. Not sure if this matters, but it has a PSC-1 Procharger. Any suggestions on where to start looking? Thanks as always!

 

[Detroit Stang]

Well, now it's really running rough. No power in low gears. Maybe it's not firing on all cylinders? Or?? Of course I've never had a car do that, so I don't know exactly how that feels/sounds. No codes thrown so far. Going to have to take it somewhere, but thought I could ask first on here, if anyone had any ideas. Appreciate any help offered!