I have changed my timing chain cover and now 2 years later the new one I put on is leaking and the crankshaft position sensor has a nick in it that looks like it touched the crankshaft. Anyone Else??

 

Welcome from Florida. Check your Harmonic balancer, it could be wobbling and hitting the cover. I had a 2003 Blazer with a 4.3 and the balancer broke and hit the cover and let the oil out but I got lucky because it broke the crank sensor which stopped the engine before it was damaged further.