I've been data logging with Datamaster I'm reading all data except O2 voltage stays at 450mv and the BLM never changes. I replace my 4 wire GM O2 with a new AC delco 3 wire, checked connection from O2 to the ECM and that is good. still no closed loop, but the car runs good off the BIN my wide band O2 shows that it's working off the tables. But it would be good to run off the NB O2. any ideas? I'm running off a emulator have not made a final chip. need help please Mike Scott

 

Make sure that the O2 sensor ground from the ECM to the engine block is there and properly connected.

RBob.

 

checked my O2 sensor wiring today got 12v on my data line when in acc and 13.5v engine runing. when I unpluged the O2 and checked the pins I had 12v on Pin A, ground on Pin B and no voltage on Pin C with acc on. checked resistance A-C pin 5.4k ohms and Pin B-C 6.9m ohms. Anybody have any idea whats going on. help Mike

 

I checked the O2 ground in the ECM connector was open , connected ground to ecm pin E15 got closed loop. thanks for your help . Now I'll have to find out why hooking up the O2 made the idle go bad up and down 1000 rpm to 800 when it idled at 590 rpm smooth? thanks Mike