1998 Chevy K2500 5.7L Engine P0108 and P0122 Check Engine Light Issue After TPS and MAP Sensor Replacement

I own a 1998 Chevrolet K2500 with a 5.7L V8 engine. I recently replaced both the Throttle Position Sensor (TPS) and Manifold Absolute Pressure (MAP) sensor, and I've verified that voltage readings are within specifications for both sensors. However, on cold mornings, my vehicle triggers a Check Engine Light with codes P0108 (Manifold Absolute Pressure Sensor Range/Performance Problem) and P0122 (Throttle Position Sensor Circuit Low Input). The codes disappear as the engine warms up and the issue does not reappear during normal driving conditions. I've ruled out loose connections or wiring issues, but I'm still at a loss as to what could be causing this intermittent fault. Any insights into potential causes or diagnostic steps for this specific 1998 K2500 model would be greatly appreciated.