I just bought a set of Pacesetter Mids for my 96 LT-1, the y-pipe will replace the dual cats. Is it necessary to reprogram pcm for headers or will I be ok? No other real mods, other CAI and Magnaflow catback exhaust?

 

You might be ok but it also might start pulling timing because of the false knock that the headers are causing. I would get a tune imo. You will gain some hp and some fuel milage.

 

I'm a little confused with your post, are you still keeping a dual catted y-pipe?
If you are not and the cats are removed, then you will have to have the codes programmed out of the PCM or get 02 simulators. I would still get a mail-order tune, it really does make a big difference, even on a bolt-on car.

 

Sorry, the y-pipe replaces the cats. I will get a tune!

 

you don't need a tune, other than to get rid of the codes for the cats. but those won't affect the running condition of the car at all.

the power you'll pick from the tune, would be similar to the gains you'd see on a stock car getting tuned