O2 sensor questions....
2004 325ci 3 pedals, 147000miles.
While playing around with OBD Fusion I noticed in the dashboards that o2 sensor one is showing no volts. Thinking that these are probably the original sensors, I decided to replace them(pre cat). After the switch, and some new spark plugs, I'm still showing 0volts to sensor 1.
Any idea what's going on here? I have no idea what to trouble shoot, or if this is somehow normal. I have no engine codes, and it seems to be running fine.
Any guidance would be appreciated.