小女子的E36 328is有問題請教

[Orangeman]

1997應該是OBDII的車，after 1996 all vehicles in the US must complaint to OBDII. 有配備輔助空氣幫浦 auxiliary air pump，台灣也翻作二次空氣幫浦，目的是讓冷車的增濃噴油在觸媒 cat. converter中燃燒，加速觸媒升溫達到正常工作溫度，達到減低廢氣排放的目的。It is controlled by engine management computer and woks for some minutes. This is probably why you feel cold start is noiser.