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2nd Gen Ram Tech1994-2001 Rams: This section is for TECHNICAL discussions only, that involve the 1994 through 2001 Rams. For any non-tech discussions, please direct your attention to the "General discussion/NON-tech" sub sections.
Routing is still fairly important. Check out the TSB. Granted, I think the aftermarket wires are actually of higher quality than the factory fellers......
Have you seen 4 volts coming from the signal wire on the upstream o2 before? Im trying to find any threads about it, but dont see anybody having this problem? Or is this normal? I'll route the wires as the TSB says but this upstream o2 is confusing me.
Signal wire from O2 sensor should bounce between 0, and 1 volts. (and all the points in between.) If you are getting four volts, see what input voltage is, it that is 5 volts, it's a bad sensor.
It starts with 4.1 volts when cold. It will start going down pretty steadily as it's running and when it reaches .9 volts it will start bouncing between .1-.9 volts like a good o2 sensor. In the time its dropping from 4.1 volts is when it is running like crap.
The PCM shouldn't even be paying attention to it at that point.
Do you have a scanner? Can you see what the voltage is when the O2 sensor shows "ready"? (or whatever other indicator it gives that the PCM should listen to it.)
I borrowed an Actron scanner and the upstream o2 shows 1 volt than drops to .1 and holds there at idle idle. About 1500 rpm it begins bouncing as it should but idle just sticks around .05-.1 volts