Going up a hill in cruise control my 4.3L V-6 kicked down a gear as usual, but this time the check engine light came on and it would not make power. It makes power as normal except under load. Autozone says the code (P0101) is a discrepancy between the actual mass air flow and the calculated mass air flow derived from other sensors (throttle position, barometric pressure sensor, etc.Autozone listed possible causes as: 1.vacuum hose off, cracked or passage blocked - Engine mechanical timing condition. 2. Throttle body intake tube loose, off, or cracked. 3. Manifold Absolute Pressure defective.

I checked the mass airflow element and entire intake manifold (filter is fairly new and looks OK) and didn't see anything. I'm not sure what or where the barometric sensor is, but I think it is just downstream of the MAF sensor. It looks intact, but that's all I know.

Any help would be appreciated!
Jake Davis
Poland, OH

i imagine your exhaust is plugged