Lack of power and excess fuel kia spor

if it's new

Change the air filter, check that the air intake tube (the one you disconnected) isn't blocked, clean the spark plugs, check the engine coolant temperature sensor (variable resistor), and if you can, check the fuel pressure regulator. If all of that fails, change the mass airflow sensor. If that still doesn't work, instead of paying 6000, sell it as is... you'll come out ahead. Good luck.