Pontiac Repair: O2 sensor Issues, copper wire, ground wires

Question
QUESTION: My check engine light is on had the codes read it reads O2 sensor Bank 1. We tested the volts it reads a steady 4.0. i know it shold be fluctuating. I have changed the sensor twice but that didn't help. Any ideas? please help

ANSWER: Hi Jess:

What model and year car is this.. If the voltage is steady on the sensor at .45V then the sensor is not producing voltage or the ground circuit to the sensor is bad. if this car has heated sensors ther are 4 wires going to the sensor. if it's an older car there is just 1 wire. And the gorund issue may be with the computer not the sensor.


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QUESTION: 96 Grand Am Quad 4 the sensor i am having trouble with only has one wire (not heated). I thought the other problem I was having was related to the o2 sensor but now I'm not sure it acts like it looses all of its power while going down the road at any steady MPH just curious if this could be computer related also?

Answer
Take a look at the gound wires on the engine to transmission bolts. The lower 2 bolts on the front side of the car which is the left side of the engine. they are uaually paired up 2 wires on each stud. Give the wires a nice tug and see if they break off. If not take a look ta them if they are corroded and Green looking "the wire that is" then replace the wire ends and cut the wire back untill you get nice shiney looking copper wire inside the insulation. The ground wires are tan, tan with a white tracer and black a black with a white tracer. If any of those wires are bad it will effect the O2 sensor and the way the computer works.. Ther is also a ground wire on the side of the block by the oil filter. Take a look at that one as well. Good luck :)