I was wondering if anyone has had experience with this code.
1995 4.5

The code that is stored is HO2S CIRCUIT LOW VOLT B1S1

Wife was driving and the vehicle started running poorly. When I went to get it and drive it home it ran fine. It had a chance to cool down for two hours.

Does this mean that the #1 sensor closest to the engine needs replacement?

thanks for your help!!!

 

its bank 1 sensor 1 which if I remember right si the 1st on driverside. It isnt absolutly a bad sensor.
Ohh and by the way you have a 4.3 not 4.5

 

The '95 will only have 1 upstream sensor and one downstream sensor. So this is the sensor ahead of the catalytic converter.

And I agree, it doesn't necessarily mean that it is bad. Try resetting the codes and see if it comes back. The fact that the truck ran worse for a bit, then got better does, to me, sound like a bad sensor. After so many bad readings, the PCM will set the code and ignore the sensor, going to a predetermined map and relying on the other sensors to run the engine. This is not optimum, but it'll get your from A to B.