Technically you are not supposed to replace any functional Cat before 50,000 miles. Moving the placement of the cats aka long tubes is frowned upon as well. Weather you can pass smog or get caught is a different matter altogether!Looking at putting Kooks headers with their green cats on my R/T. Are these emissions legal and/or will I pass smog?
Which means not smog legal in CA.Cats Are 49 State EPA Legal