I have an odd problem with the lambda reading on my car. It has a PowerFC with Commander so I can see what the sensor is reporting. On boost it shows .88v - .90v which although quite rich is ok. But when driving of boost or parked up the sensor reads 0v where it should be oscillating between 0v and .70v. The sensor has been changed several times with the same results. Can anybody suggest what I might look at next please?