gte code 31 (maf) only active at idle

[Nick M]

after searching a bit i read something that the ecu doesnt use the karman signal (ks) at cranking, is this true at idle as well? does anyone know what signal it actually uses during cranking? i assume something from the tps or cps?

Yes it is true, and already answered. When cranking there is a signal just to let the PCM know you are cranking the engine and need fuel.

Ignoring the 31 AFM code, the symptom is a bad meter. When you have more engine speed, the sensor is able to move where as at idle, it is gummed up from too much oil on it. Which is typical of an after market filter. If we had a MAF, you would just spray it with electronics cleaner.