[theWalkinator]

Long time looker but first time posting.

2001 boxster 2.7, got 4 codes, P1126, P1133, P1128, P1130.

I know this has been beaten to death but for the life of me I just cannot find where is the leak, here is what I have done so far:

1. Cleaned throttle body
2. Replaced AOS
3. Replaced MAF with Bosch one

Smoke tested from the intake duct right after the MAF, find no other leaks except a very small leak from the resonance tube nipple which is the pivot point of the resonance flag, I use a cap and epoxy to seal the nipple and no leaks after it is sealed.

Here are some data points from my scan tool:
EOBD mode:
MAF 2.75 g/s
Bank 1: STFT 1.562% LTFT -0.781
Bank 2: STFT 3.906% LTFT -0.781

Porsche Mode:
Bank 1 FRA 1.00 RKAT 4.17
Bank 2 FRA 1.00 RKAT 4.50
MAF 10.1kg/h at 1.27v

So definitely the car is running lean and idle is unstable, it surges up or down every few seconds, but smoke tested multiple times, no leaks in engine bay, no leaks under the car and no leaks in frunk brake booster area. Also did multiple times battery disconnected and reconnected, turn key on for 1 minute the pull the key out, wait for 10 seconds then start the car to force ECU to re-adapt, still no luck, clear the code and short drive for like 20 minutes codes come back. Car still drives fine even with those codes.

The only thing that I didn't do is to test fuel pressure, my HF fuel pressure test kit does not fit the Boxster fuel rail schrader valve so need to buy another one.

What else? The vacuum reservoir? If the vacuum reservoir starts building up vacuum then loses it, would that cause idle to surge and fuel adaptation codes to be thrown?