oil cap

I can't get my oil filter housing cap off and the only way I'll get it off is to drill into it and destroy it basically. SO after I do that, I'll need a new one. Anyone know where I can get just the cap? ECS has the whole assembly, that's it. ...this is what I get for having someone else...

The other day it was raining and the roads were wet, i never beat on my car so i did a little burn out while it was wet. Right after i did it the idle was jumping from 700 to 2000 up and down and wouldnt stop. Also had it had like no boost and check engine light came on. Looked under the hood...