lol.

O2 sensor isn't going to do this damage, it would just run a bit rich, and throw a cel.

You have not installed your timing belt/cam gears correctly and it has cost you your engine....

OEM cam gears and belt is hard enough for the average home mechanic, let alone adjustable cam gears!

It's a costly mistake, but hopefully one that you can build on. Now, do it once, do it right...