Fuel pressure is fine on ricky's car and when the problem occurs the fuel rail does not feel hot at all. This seems to be a different issue to Jamie as his only happens in traffic.
Ricky can be driving the car any way for an hour or so and the problem is there, afr's start to drop slowly untill the car is undrivable.
The injector thing is the opposite way round, high impedance should run cooler.
Also when the car was first mapped it was mapped hot, this ment the problem was reversed and the car ran fine when after an hour or so and rich before that.