Reading about the air filter hose and swapping different MAFs in makes me wonder if the wire harness or connector for the MAF is damaged.
Any potential air leaks between the MAF and throttle body?
Also if you search for the P1130 you will find some threads where it was a problem with the evap purge valve:
https://986forum.com/forums/boxster-general-discussions/67910-fault-code-p1130.html
Also check again for more vacuum leaks - Brake booster vacuum hose, oil cap and fuel cap, hoses connected to the AOS.