PSA:
I wanted to make folks aware of a small issue and general recommendation I make for all stage 2 and higher cars I tune via Cobb. With catless, high flow catted, and O2 spacer downpipes, the ECU will slowly add extra fuel at heavy load and will end up running fairly rich over time. This is a function of the rear O2 sensor being used to determine cat efficiency. Since the factory cats are not in place, it gets confused and continues to add fuel.
I have made Cobb aware of the issue and hopefully we will have a software solution eventually. But in the meantime, I recommend that people unplug the rear O2 sensor and leave it unplugged. The easiest place to do it is under the hood at the firewall. You will find two connectors here... disconnect the black one only. After doing this, I also recommend reflashing your latest map to reset any learning the ecu has done. Once this is done, your air/fuel ratios will remain consistent.
