The idle thing again

[TomEboi]

Thanks for all the replies. I picked up the car last friday. I started it up and it was DOING THE SAME THING! Let me explain exactly what it is doing. When I rev the car in neutral or anytime I have the clutch in and am coming down in speed (like to stop at a light), the rpms will go down to about 500, then go up to 800 or so. Sometimes it will come down to a little less than 500 and you can tell that it may stall, but it recovers to about 700. There are times when I feel that it actually will do the correct thing, which is when I put the clutch in it will come down to about 1000 then, when I completely stop, the idle will go to about 650 very nicely. But, the next time I go to stop, it will do the drop then raise deal. I know I need to take it back to the dealer. I am just so pissed cause here I have my dream car and it is in the shop already! Also, to answer a question, yes they said they hooked it up to a computer and that is where they say the fuel pump was messed up. I am looking at my receipt from Ford and the code says "42". I am not sure if that is even the code, and I have no idea what it means. Any further thought? Thanks