The P0101 can be caused by the following:
1. The harness to the MAF sensor is routed too close to: (a) the secondary ignition wires or coils; (b) a solenoid, (c) a relay, or (d) a motor.
2. A low minimum air rate through the sensor bore at idle or during deceleration caused by: (a) deposits on the throttle plate or in the throttle bore; (b) any vacuum leak downstream of the MAF sensor; or (c) any contamination or debris on the sensing elements of the MAF sensor.
3. Water intrusion that reaches the MAF sensor.
4. Any significant restriction in the induction system or the exhaust system.
5. A defective MAF/IAT sensor.
6. A skewed or stuck Engine Coolant Temperature (ECT) sensor.
7. High resistance of 15 ohms or more on the ignition 1 voltage circuit. (This high resistance may cause a drivability concern before this DTC sets.)
8. High resistance on the low reference circuit of the Manifold Absolute Pressure (MAP) sensor.
9. A short to voltage on the 5 volt reference circuit of the MAP sensor.
10. A restriction in the MAP intake manifold tube.
11. Any leak in the throttle body or intake manifold, including an unplugged MAP or brake vacuum tube.
12. A defective MAP.
Edit: Supplemental Info
Since this error code can be caused by intermittent signals from powertrain management sensors (MAP, ECT, or MAF) another potential cause is bad grounding caused by oxidation of the engine harness-related grounds. This oxidation is not readily apparent because it does not look like the corrosion that can develop on battery terminals. The fix is to pull the grounds and freshen them with some abrasive material - star washers can also help.
The critical grounds on the CTS-V include: the negative battery terminal; the ground located just beneath the hood stick mount; the ground located on the back of the passenger-side cylinder head; and the two grounds located on the back of the driver's-side cylinder head.