Ecotec Ported Head Wire Harnesses & Adapters patent-pending X-Digital technology that makes

patent-pending X-Digital technology that makes them the fastest responding wideband air/fuel ratio controllers in independent testing against 17 other wideband UEGO air/fuel controllers

The XPZ requires ported heads with machined valve guides

2007 Chevrolet Cobalt LTZ Sedan 4-Door 2

2008-09 Saturn Aura Hybrid for L4 2

Ecotec Ported Head Wire Harnesses & Adapters patent-pending X-Digital technology that makesA ported head increases airflow by reducing restriction therefore more high rpm horsepower. Increasing head flow creates more horsepower at the same boost level and works very well with aftermarket cams. LSJ: All flowed at 28", 3. 5" bore plate, exh had a 1 5 8" flow tube, and stock valves (int. 35mm, exh. 30mm). Do NOT be fooled by other venders flowing heads without a flow tube, in the real world people run headers, not open heads without headers or