Help wiring in my wideband

[chris023]

Hobbyist mechanic checking in.  I have an old AEM UEGO 30-4100.  How good/bad will this reading be for my tuner? I didn't realize how old this setup was and am wondering if it is worth wiring in.

The power loom has 4 wires:

1. +12v switched (recommended 10a fuse)
2. Ground (to ecu + chassis?)
3. 0-5v out (to ecu)
4. Serial out (don't need)

It seems pretty obvious that 2 and 3 should go direct to ecu to ensure an accurate reading on the 5v.  My question here is that since the sensor and display share a ground and there is not a separate ground for the 5v signal, can I use the ecu ground for the whole setup or should I split 2 and have a larger ground that goes to chassis with a small ground for the 5v signal that goes to the ecu.

Thanks in advance.

[Adamw]

Since the shared ground has heater current/noise passing through it you dont want to connect it to ecu sensor ground.  Usually it is best to connect it direct to engine block as that can pass the current and usually has little offset compared to ecu.