the solder points inside the afm probly broke apart, same thing was happening to me i wud be driving along and then car wud shudder and jerk back and forth under acceleration,(r33 tho)
dont throw the afm out dude, it can be fixed
u have to get a stanly knife and cut the silicon seal around the side cap out, take that off and u shud see a copper plate, remove that and u will be able to see the circiut board and there will be three metal pins that join up to another set leading down to the fillament, the solder used to join these is shit and breaks easy, so just get some more and resolder them, i made sure ther were lots of solder on each connection so they dont break again, then just put the copper plate back in, put the side cap on and reseal it with silicon again (i used sensor safe black rtv silicon) and voila car drives normal again.