Your csi injection system was built to last, the computer under your rear passenger seat were made stronger than these new computer brains, but if one goes bad which is seldom, the price tag is kinda steep, for a used or rebuilt version we are talking about $1500.00, i inquired around about purchasing a backup just in case, and bmw na does'nt carry them any longer, but you can still order the injectors thru the dealer,also at maximillian..good luck, Randy 72 csi