interesting problem
ok so here is my issue. i have a 99 sentra with a 2.0 swap and a 95 200sx 2.0 manual ecu. i had a code for the rear o2 sensor because i didnt have one hooked up. p0136. so i made a simulator and it is indeed cycling between .1v and .9v about every 3 seconds but im still getting the code and its reading zero voltage on the scan tool. i hooked into the rear o2 sensor signal wire at pin 52 and its getting varying voltage all the way to the ecu but its not registering it for some reason. i even tried another ecu from an automatic with the same results. please help meeee....