Need help diagnosing car problem! my car makes a clicking noise through low gears?

[ImmaBayBoyBayBee]

while accelerating and slowing down. more so while slowning down. only way i can describe it is the noise smokey's car make in the movie friday.
http://www.youtube.com/watch?v=18oUuqoZNYI
the sound it makes at about 2:35 into the clip minus the backfiring noise just the clicking noise. but mine is when my car is running