Actually, on his '99, the o2 is in the collector pipe shortly before the cat. Dodge changed the cat setup in 98 to SI/SO and moved the o2 forward a bit.

Not saying he didnt smack it, just that it's harder to do with this setup as opposed to the pre-'98 one.

Glad you seem to have it fixed (*touch wood*) velocity37; give us the final word when you are certain.