Thanks Brian, that's really helpful. I kind of figured that'd be the answer, but I just wanted to be sure. Yes, slight puddle forming in the dish on the first O2 sensor. I tightened it down a little more with a proper O2 sensor wrench, and it seems better. It's also smoking a lot less now. Guess that's just normal like you said; hopefully it'll go away after I put some miles on the car.
2006 MX-5, marble white with black OEM hardtop: Flyin' Miata Stage 2 suspension, Flyin' Miata exhaust, GWR Helmholtz mid-pipe, Hard Dog M3 roll bar, Hawk HP+ pads, stainless steel lines, GWR/Moroso aluminum coolant overflow tank, Voodoo shift knob.