2000 Pontiac Grand Prix- Antifreeze and heater

I needed antifreeze. Grabbed an antifreeze container and started pouring, I had drain oil in the container. I didn’t pour much in how ever the heater doesn’t put out much heat now. Will a radiator flush take care of my heater problem?

I doubt the heater problem is caused by waste oil in the coolant. A flush to get the oil out is a must but don’t expect your heater to start working again. Post back with what you find after a flush and tell us a lot more about your car so we can help.