My engine is leaking oil and the engine is throwing the knock sensor code?

The engine oil leak and the check engine light are two different things. The knock sensor issue is driving the check engine light, but troubleshooting is needed to find out if you have a sensor issue, a wiring issue, or an engine timing issue. The oil leak - have everything cleaned so no oil is present, add dye, and then drive and check for a leak source using a UV light.