2010 Aveo Ecotec low power, no codes

[auto_19]

Hello, I bought a 2010 Aveo ecotec automatic which had an oil consuming engine issue. I rebuild the engine and since then, it didn´t had the power they are known for. No trouble codes, ECU with the last calibration file, changed every sensor and actuator and the vehicle has no acceleration. MAP sensor Kpa readings are low, 40+ at idle when a similar vehicle has 30 or less, and 70+ with a/c while driving, even the brakes feel hard because the engine loses the vacuum. Even without a/c has poor acceleration. Checked vacuum leaks, exhaust leaks and restrictions. Spark in that condition is -15 which is an odd value which I am wondering what causes the spark to retard that much. Engine with 160+ PSI compression and even had the opportunity to test a new engine with the same results. Anyone had this experience on to what may be causing the issue?