I have a 1997 Chevy Silverado 5.0Liter 302. what does "O2 Sensor Circuit Low Voltage (Bank 1 Sensor 3)" mean?

Answer 1

i think mtech has made a very well informed, logical answer. i, however have rarely found this code to be anything but a bad sensor. sure, take a look around the wiring harness to make sure it hasnt melted on exhaust, and make sure you know which sensor is which, but i think you would be making a good gamble by replacing it with a cheaper aftermarket part. it will cost .5 of oem, and .2 of a shops labor, parts markup, and b.s charges. if the code comes back, the part stores usually will refund your $, save the box and old part, and say that it looked used when you bought it. dont get me wrong, mtech is a sharp mechanic, but i think you can save $$

Answer 2

This means that the powertrain control module has noticed, according to it's threshold minimum voltage over time, that the rear oxygen sensor on the bank with cylinder #1 is below .3 volts for too long. It should hover around .450 volts for the majority of the time since it monitors catalytic converter efficiency. I know that most of the answers to this question will say replace the sensor, and buy it cheaply at a discount auto parts store, but I must humbly disagree. Notice that I said that the computer THINKS that the voltage is too low over too long of a period of time, but what if a wire from the sensor reference signal wire is open because it has hit the exhaust manifold and melted? What about a corroded connection? What about a failed sensing circuit within the powertrain control module? I recommend having a true, ASE certified technician evaluate the problem before buying this part because you may be throwing money at the vehicle. Also, if it does end up needing that part, I strongly recommend buying one from the GM, because of the sensitivity of the component.

Answer 3

provided the rest of fuel system is functioning properly, injectors etc....you have a failing catalytic converter. from what you have mentioned. hope this helps