i never said it should be hitscan , but it should be a tighter hs box than it is because right now it ' s not accurate <| sep |> Holy fuck that movie <| sep |> No whipped cream vaguely resembling two hands ? Huge missed opportunity . <| sep |> Sometimes things just break and sometimes they break while at the shop . Sometimes computers go bad . I ' m skeptical in this situation though . I ' ve had it happen to me as well . fix one thing and something else breaks . When it happens you call the customer and explain what ' s going on . You getting in the car to discover a blinking check engine light seems kind of fishy though . Them telling you to drive the car anyway with a blinking check engine light is horrible advice . Add it all up and I ' ve got a vote of no confidence for this shop . Lots of computers get replaced in the chase of an elusive problem but the computer is rarely the actual issue . I doubt that your car has fixed itself in this case , your check engine light is likely to come back again . With that said I also doubt that it ' s a computer issue . Much more likely some wiring was disturbed or damaged while changing the alternator . If the light is off now I would drive it and see what happens . If the light stays off then you ' re golden . If not then I would take it to a dealer for diagnosis in this case . You ' re going to pay them a bit more for a diagnosis but they also see a lot more of those cars . Did you already pay for the computer ? If not I ' d tell this shop to return it . There ' s no reason they can ' t return an unopened product . Perhaps there will be a restocking fee and you might offer to pay that if you intend to use this shop in the future but I wouldn ' t let them replace the computer in the car under any circumstances .