Spartan 2 Wideband reading rich and inconsistent readings

Hi guys, I am in the midst of installing a Spartan 2 wideband inline controller in a car with a Link G4+ Storm Black, I have it wired to 12v from a relay and grounded to the same ground as the ECU and the linear output going into AN Volt 8 with the signal ground into the Gnd out next ANV8 on the B Loom connector.

Originally when first installed it would show irregular readings jumping around between rich and lean, but I have since replaced the sensor witch has fixed the irregularity but now seems to read rich, however it does read lean during decel on overrun as it should but during load its stuck at 0.68 lambda and will idle at 0.70, if I lean the car out to match the sensor its starts to run rough and die (sounds/feels lean)

I have been chasing my tail for a couple of days now trying different grounding points as I have had issues with grounds on other controllers before, but none of it seems to help.

I have checked that the controller is calibrating during startup witch it does, starts at 1.33v goes to 3.33 but then goes to 5.03v instead of the recommended 4.98v

does this sound like a dead controller?

Any advice will be much appreciated

Attached is a log and tune file

I would be suspicious of the controller based on what you have stated. Assuming your replacement sensor was a genuine Bosch.

The only way to verify the accuracy is to compare it with something known good. If you know a welder you can hold the probe in nitrogen or argon and it should read 1.0 Lambda, or another quick test I have done before is slide the sensor into the tail pipe of a stock modern car as they nearly always run closed loop Lambda 1 at idle - if it still reads rich in one of these tests then you know it is faulty.

Assuming you were using cal 4 in your ecu then your set up looks like it was ok.

The new sensor was purchased from NZEFI so would say 100% that it's genuine, might try put the sensor in a tailpipe of a newer car we have at home, as you have said, as I don't have access to nitrogen/argon.

Using cal 4 with the data provided by 14point7

Thanks for your input Adam will try this out

cheers