So before I did my head gaskets a month ago, i got the p1412 occasionally. Now I get 1412 and 1415 every single time. There is not much that is original left under the hood.
I have replace the Hyundai purge valve a few years ago, it could be bad I suppose. The IAC valve was heavily cleaned, appears to be fine. I dont have a vacuum leak that I can find.

At this point, I am fine with throwing parts at it and was thinking about just replacing all the vacuums lines. I am reasonable certain the SAI valves are fine, I cleaned them heavily and they hold vacuum.
The SAI pump is noisy sometime, loud, probably bc it is an ebay one from several years ago. Worn bearings likely.

Any other suggestions on what may need attention? Parts that I may be overlooking? Do the codes indicate where the leak could be from, eg before the MAF? or otherwise?
RAVE says: NOTE: A malfunction of the valve is logically expected to result in both engine banks reporting the same fault

 

Those vacuum lines get really brittle over time and crack, I would start there.

 

SAI codes, start by checking all the hardware for function. Exhaust manifold valves, blower function, vacuum solenoids valves.

 

with the car off for about an hour, when i unplug the left ha d hose, there is a sucking sound, its under vacuum until i release it. Is that what should happen?

 

Interesting test, yes that is basically what should happen. What you have confirmed is that when the system is exposed to engine vacuum it is tight and will hold that vacuum. What we do not know is if the solenoid valve that commands the Sai valves in the exhaust manifolds to open is working correctly. You can put an OHM meter on it and make sure that it is not open or shorted or you could apply 12 volts to it maybe from a battery jumper and make sure that the solenoid valve clicks and that you can blow through it when it is energized. The other thing we have not confirmed is if your Sai blower fan is running, when you start the car from a cold start the fan should run for about 1 to 2 minutes. If you have not heard it running it would be good to jumper across the Sai fan relay plugs to make sure it will run if the relay is energized. You can also double check the relay for proper functioning but they very rarely go bad.

 

It runs sometimes, only when it is cold enough outside I suspect. I will certainly double check that. I will check the solenoid next. I had replaced it a few years ago w the Hyundai one, I certainly could have done something to it during the head gasket job.