P1504 - what are all the reasons for this code?

Question

My son has a Lincoln LS and when he starts car it stalls out. He gets P1504 code but it's not the air intake circuit thing. What else could it be?

Answer 1

Hi there,

If the problem isn't with the idle air control, then look for intake manifold leaks after the mass air flow sensor or a problem with the maf sensor itself. Sometimes if you unplug the maf sensor and the car will start and idle on it's own you now the maf is bad and it should be replaced.