Thats because white is basically a clean earth through the ECU as far as I know. Blue is supposed to flap all over the place, thats how the sensors work. If you stay too high or too low under certain conditions then it throws up a fault code.
It should vary all over the place (going high then low then high etc) once its warm. Probably reads very lean while its cold. Should also read slightly rich at full throttle and stay there until you lift off. At cruise and possibly at idle it'll vary all over the place
Normal operation will give big variations from lean to rich when
revving the engine. Even at steady throttle there can be small
variations as the ECU adjusts the amount of fuel +/- to try and
achieve the optimum A/F ratio. Big variations at steady throttle
say you have a problem
Cheers.... jondee86
1984 AE86 Corolla GT Liftback, NZ new... now with GZE spec small port, twinscrew s/c and water/methanol injection
under boost, right round in rich
under engine deceleration (sp?) off the scale in lean (no lights on at all)
normal driving red/orange/green flashing all over the the place
is that right?
its like a freaken disco in my car atm!