Error Codes; PO171, PO174, PO1150, PO300

[jared_801]

I've got a 2001 Toyota Sienna XLE. Just put in all new belts, and replaced the left (front) cylinder head. I got it running but it does not idle well and I've pulled the following codes:

Error Codes; PO171, PO174, PO1150, PO300

I know what all the codes mean. I think I can hear a vacuum leak which would cause these errors. Next most likely suspect is the Mass Air Flow sensor (MAF). Anyone else come across this same issue?

[jared_801]

Well I've found a hose I forgot to put pack on. That fixed that vacuum leak. I cleared the coded then after a test drive P017 & P0174 came back on. I cleared them again and they came back on.

The van is running much better. Where should I start?