[MiracleMax]

Have you done any mods?

IMO, using cut outs on a stock engine might not be worth anything. The stock exhaust system flows pretty well at the stock level.

with a t-body and cat-backs, I've gotten a WHOPPING 6 hp. (not that I expected a whole heck of alot anyway).

but it illustrates the point.

Now I gotta ask, whats the reason for putting the cut outs upstream of the EGOs? I dunno about the current EECs, but in times past (EEC IV). The EGOs would go open loop under full throttle, during closed loop they would fine tune the A/F mixture.

Now, if your planning on diverting the exhaust flow ahead of the sensors then it will more than likely throw a code or put it in limp home.