Originally Posted by JSarv
Front o2 Sensor scaling is improper for USDM applications. You have 2 choices - 1. Rescale for your stock roms o2 scaling 2. Move your front o2 Sensor to the Downpipe.
That's fantastic news! Always wondered if the car would run the same if I just moved the O2 post-turbine. This'll let me get some semi-legitimate AFR readings using the stock sensor even under boost!
Wait a minute... After comparing my 04 WRX ROM to that Group N ROM, the Front O2 scaling isn't any different. Every mA value corresponds to the same AFR. The only difference is the Group N ROM has more cells so the O2 sensor is scaled down to 10.x instead of just 11.36... Is there a huge difference between your 02 WRX ROM and this Group N ROM?