I was asked a question the other day about a problem with engine dying at slow speeds and at stops. If you have a fuel injected engine (just about everything after 1986) then you really should check and clean the throttle body FIRST before you do anything else.
If the throttle body is dirty it will cause erratic idle speeds, rough idle complaints, dying at slow speeds and at stop/idle and sometimes will produce an extended cranking time when starting.
Just about ANY auto repair shop or fast lube place can clean the throttle body for you while you wait. You can also clean it yourself with a toothbrush and some spray intake parts cleaner you can buy from your local auto parts store.
If you have a Ford product you can also clean the Idle Air Control valve as well – IAC Valve. Remove it from the engine and disassemble it for cleaning with the toothbrush and some raw gasoline. There is a sticker on the valve which says dont use intake cleaner – I have and nothing bad happened but to be on the safe side use gasoline and the toothbrush.
This is a dirty throttle body – when you step on the gas pedal that gold looking flapper valve will open up. When the seal around the flapper valve is hampered with sticky carbon dirty build up the problems I mentioned above will take place.