Does the secondary o2 sensor have to be plugged in when you install a o2 simulator to your ecu? I installed my o2 simulator to my ecu and i didn't work but i also didn't have the secondary o2 sensor plugged in.

 

which simulator do u have? how did you hook it up? i'm pretty sure the o2 sensor has to read something. are you just leaving it outside of the cat/testpipe? try wrapping the o2 in foil. i heard that could help.

BUT...did you reset your ecu after you put on the simulator. a CEL will only turn off my itself in certain procedure. so reset the ecu if u haven't done so.