Random Lean Mixture

[AJ2g4g63]

Searched for hours about my specific problem, and while there are a lot of threads about lean behavior, none matched my specific symptoms.

I fully built my 2g from the ground up. Running walbro 255, precision 1000cc and a 16g maxed out at 25psi. I also have an AEM Eugo Wideband. During my tune, it idled at stoich (14.7:1) and pushed 12:1 at WOT.

Just recently, it started acting really weird. Idles above 18:1 and pushes 15.6:1 at WOT... Needless to say I haven't touched boost since I made the discovery.

Things I have already checked/ done:

Properly cleaned injectors
Changed spark plugs
Replace fuel filter
Checked fuel pump
Checked compression (good)
Checked for vacuum leaks (none)
No shaft play on turbo and pushing same psi as before

Seriously concerned and confused

Also, the car always misfires at constant rpm over 3000. I just turn the key off and back on while still in gear and it goes away for 5-10 seconds and repeat. So generally on the highway. I have a feeling like these issues are related. I'm tuned on black box, so I can't adjust my afrs.

Please help.

 

[thearkatek]

Boost leak test?

Edit: Sorry missed that!