Brian wrote:The first O2 in the system is the Wideband and needs to be in the system for the car to tune itself, adjust fuel trims, etc.
The second O2 in the system is just to check function of converter and it can be removed and turned off in the calibration by the tuners like Mike at Motoeast.
Thanks Brian...that is what I thougt. The one is referring to was the downstream sensor. The upstream was fine!