Damn cant we all just get along? Alright i design custom exhaust on the side, You DO need a o2 BUT there is an very easy an very cheap way to get around it, i also have a 1999 4x4, an i'm in the process of doing a custom job on it, 2 straight's from the header's WITH a hallow cat, you can still use your regular cat an just hallow it out, or if you have inspection's simply just gut it weld a piece of exhaust pipe in the middle an call it done, although unless you live in ok or ma which actually have a "smell meter" if u will that can actually detect the difference in factory or modified.

 

lol you dont have to one that sucker of mine they way its done i can kill mysqitos lol