2007 Vectra 1.8 petrol. p0100 fault need help.

[Langley863]

So my Vectra 16v 1.8 petrol is running perfectly fine has power were it should with no stuttering or smoke coming out the back however I have a p0100 fault code read using my OBD2 reader. I've erased it but it just come straight back and because of this my emissions warning light is on. I've replaced the mas sensor itself and that hasn't cleared it. I've been told about an issue where you need to re-earth the sensor but I can't for the life in me work out which is the earth wire I have a green/white wire a green/brown one a red/blue one and a black/purple. Can anyone shed any insight into how to fix this I'm completely at a loss as the car is running perfectly I just can't shift this fault.
IMG20201201163924.jpg
I've attached a picture of the connector if that helps but I'm at a loss and need to drive 400 miles on Thursday and really don't want to be breaking down on the M1 so any help would be great thank you.

[troutybrown]

Did you replace with genuine or aftermarket?
Vectras don't like aftermarket sensors.

[Langley863]

Genuine Siemens sensor it's replaced with.

[troutybrown]

As for the wiring there was a issue with the astras where the loom could corrode done one on a astra g many moons ago but havent heard anything about your engine.
I would check the wiring from sensor back to ecu.
Also have you got anything to check live data?