I have a W reg Volvo S40 and I had a new Cat & Air Mass Meter (?)
installed which must have involved disconnecting the battery for a
substantial time, because when it came back from the garage, the stereo
wanted me to input a code which I don't know.
I've heard that you can freeze stereos overnight to disable this
security feature, but I'm concerned this may also damage the stereo
itself.
Can anyone confirm whether a) the freezer does remove the code and b)
the freezer won't kill the stereo?

Thanks