AEM X-Series OBDII Wideband UEGO AFR Sensor Controller Gauge vendor_Wilwood and they will tell you

and they will tell you that the best bang for the buck handling mod you can give your STI is a high-performance swaybar

Part #: MBK1009

Improves engine cooling and performance

it will reduce the horizontal movement by up to 0

AEM X-Series OBDII Wideband UEGO AFR Sensor Controller Gauge vendor_Wilwood and they will tell youAEM's X Series OBDII Wideband UEGO AFR Sensor Controller Gauge (PN 30 0334) provides tuners who are using piggyback tuning modules or open source software with the ability to view AFR through the factory CAN bus stream that is output by the factory ECU, and deliver the most accurate, safe and powerful tune. The 30 0334 X Series OBDII Wideband Gauge is verified to work with HPTuners and DashDaq, with more applications being validated. The X Series