If the sensor that was replaced wasn't a OEM part it can cause many other issues. Black smoke generally means something to do vacuum problems. If the ignition coil bad you can also check if the spark plugs are the cheap ones. I've notice that very cheap spark plugs gets burnt out quickly and usually cause the coil to afterwards. For that car only iridium spark plugs should used. Find that vacuum leak, renew the spark plugs and coil and if it's a direct injection engine , the intake manifold should cleaned as well.
Noted sir, that's why the p0303 pending code I found kind of point my scope towards those ig, it is certain cos the car is used by a woman. There's is little to no maintenance.
