No idea what the air gap is specified, but what ever it is ,it is not adjustable.Why do you think the rear sensor is faulty?

My ABS light came on I took it and got it diagnosed and it was the N/S rear, I replaced it but when I first fitted the new one in to its fixing hole it didn't go in straight, so I spent ages with a needle file cleaning all the rust out so the new sensor just slid in. It put the ABS light out straight away, sorted I thought. It then came back on again a few days later, I had the car checked for any DTC's, there were none and the faulty sensor DTC had cleared. The ABS light is coming and going now, I have been told it is possible to get the sensor in slightly wrong if it's seat where the bolt fixes isn't totally clean. So now I want to double check it is correct and at 90 deg to the ABS ring but would like to know the what air gap so I am happy it is in right.

Andrew...

Hi yes it was a aftermarket one as a OE one is £175.00, I thought it has to be worth trying one first.