I am going to replace my exhaust system in the near future. I have dual cats on it right now(cats are bad) and I going to put back on the single cat which was what came on my car originaly. I dont have the n10 option on my code label. I have stock manifolds and a new replacement y-pipe, just have to get a cat back and cat. Would there be any gain if I relocated the o2 sensor down towards the cat so it reads all 8 cylinders instead of just 4? Thought it might run a little better and get a little better gas mileage reading all 8 cylinders.

 

no, whether it reads 1 or 8 cylinders, it will read the same.