exhaust sensor readings bad [V6]

[Skylarking]

Once in closed loop mode, the ECU will swing the fuel mixture from lean to rich about every second so the O2 sensor voltage will never be static. O2 sensor voltage should swing from 100mV to 900mv during normal operation.

If things seem erratic, that’s probably the scan tool so try another scan tool or better still try and measure the O2 sensor voltage directly using an old analogue volt meter (where you’ll see the swings will be nice and clean like the beat of a metronome)

 

[Drawnnite]

That reminds me.
Have done the voltmeter test before (you do need to get some very fine probes or similar to backprobe the plugs)
If you have a really good quality Digital Meter that can work aswell. (Ie i can set my Flukes up to read very quickly)
But an analogue one you can pick up really cheap from places like Jaycar.

It is a very fast change in values which is why many digital meters wont work.