what might be the problem if my nissan sentra 2001 gives out huge smoke through the exhaust pipe anytime i step on the accelerator%3F

What color is the smoke? Blue = Gas or carburetor problem / Black = Oil problem White = Coolant problem.

What color is the smoke? Black=unburnt fuel, white/gray/blueish = oil. If it's oil, could be piston ring(s) just for starters, among many other scenarios. Black would be injector problems, or ICM , the 'brain' bad, not sending the right fuel- air mix ratio, bad plug wires and/or plugs causing misfire ans no spark to one or more cylinders, fuel passes thru uningited therefore not burned and passes through, there is the black smoke. This is a very short list of what could be wrong. Run a fault scan, see what code comes up

HRecore you got it backward. Black is fuel. See my post please

My 1996 Nissan sentra 1,6 after I had removed the top cover on the engine for sealing up the oil leak and place it back I drove it for 1 kiometer and started bringing out a grey smoke that doesn't stop