We were using new pins, but all three harnesses had the exact same problem; so we thought it was not likely a pin problem. In the end the problem was related to the O2 sensors we were using. We found information regarding isolated ground O2 sensors vs case grounded O2 sensors @ http://www.lt1swap.com/vortec_o2_sensors.htm that helped correct the problem. Just like some LS1B ECMs do not support electronic throttle, LS1B ECMs are designed for use with one or the other sensor. It appears in either case the ECM will see the O2 sensors if the O2 low reference pins on C1 are tied to engine ground. Right now all is happiness......Originally Posted by Team208Motorsports
