I have just purchsed and cleaned a used airflow meter for my 1990 3.9 v8 to try and get my mpg above 9.3 (and that is driving gently).

Is there anything I should know before fitting it?

I would rather not disconect the battery again as I am getting fed up programing the stereo !

If its the same as mine just pull the plug off the Air flow unit. I have done it considerably and no problems. As long aas the ignition is off there shouldnt be any power going to the thing.