Here is my 2 cents worth.
When an engine bogs it means two things,
One: its not getting enough fuel.
Two: its getting to much air to support combustion.
Test fuel pressure, it should read 43.5 psi, this is tough to complete, these engines do not have a test port on them. I just hook up a "T" with a pressure gauge on any connection going to the fuel rail.
Mass air flow sensor is sticking or not reading correct air flow. Spray a high combustable fluid from an aerosol can around air intake lines and fuel injectors when motor is at idle. If motor speeds up, you found an air leak where you were spraying. If nothing was found, test MAF with volt meter, if faulty, purchase new MAF (very expensive $231) or take apart/adjust needle, ( not recommended if you don't know what your doing).
