Lean Idle after Timing Belt Job
 

Howdy y'all, I figured this was the most appropriate sub-forum to post in!

I have a 1.6 Miata w/ a Kraken Turbo kit on it and MS3Pro, before doing anything of this work the car was running and driving great! About a month ago I decided to finally pull the trigger and take the engine and trans out of the car as I wanted to button up a few issues and figured it would be a bit easier to yank everything; timing belt, water pump, front and back seals, coolant re-route, PS delete, etc, etc. Last week I got everything back into the car and started it up, but I noticed that my idle is really lean, 19-21 AFR. I don't think this is a tuning issue as the car was running perfectly fine before hand, and would love to get a sanity check on other mechanical things that I could have missed here. I could "fix" this problem by just dumping more fuel to hit my target but there's obviously something else I'm missing here. So far I've...

* Triple checked that base timing is correct
* Confirmed that I put the fuel lines back on correctly
* Vacuum line inside the MS3 is not kinked, and the line running from it to my intake manifold is secured
* The fuel pressure regulator vacuum line is secured
* I've re-calibrated my O2 sensor from Innovate

I can feel some exhaust leak when I put my hand between the exhaust manifold and turbo itself. Unsure if this is the manifold to the engine, or the v-band between the turbo and down pipe. It was just too hot to deal with yesterday so decided to let it cool overnight and come back later today. Although I can't imagine that this would be causing me to be ~5 points off, but I've been wrong before.

Is there any else obvious that I might be over looking here? I know it's a bit of a can of worms since I've touched a lot of things.