JeromeS.

Well, i finally got a hold of a used 4kq cat. It took me about an hour to hollow the damn thing out! That ceramic **** is tough..along with metal mesh. I can see how some performance will be gained...I never knew how restrictive they are (I couldnt even see through it!). Anyways, My plan is to get a new O2 sensor for this hollowed cat. Should I do it, or just use the old o2 sensor from the real cat. Any suggestions would be helpful! Thanks.