also the knocking could be a number of things...

1. it could just be the valves hopefully
2. it could be that your low on oil and if you add some it goes away
3. it could be that you spun a bearing

so it can be a number of things

like if you spun the bearing it would also cause the check engine light

and for the smoke like AwwsChwA said its probly your pistion rings do what he said about that lucas oil... it can't hurt to try to help it...