this morning im driving home and my speedo is dead. everything else works. and speed starts goin crazy ... acting like an afr guage basically.
I got a CEL and its code 41.
i have p28chipped b16a2 obd 2 to obd 1.
on ht it said primary oxygen sensor heater
*ALSO my volt meter goes from 13-14volts ..keeps going back and forth and the CEL light also goes dim than brighter again, if its an emissions problem why is the power acting weird.
(put in new alternator-did not fix it)

 

So...did you test the primary O2 heater with a multi-meter? Spec is 15-40 ohms.