hey, what does it mean when a car backfires after being gunned to the redline somewhere while dropping back to idle?? What do i need to change. and does a head gasket matter?? also if it's hot, my car's rev will be WAY higher than normal and as soon as it hits a point, it drops, then goes back up, then drops, then goes back up, then drops, in about 2 second intervals.. one more.. when im slowing down and im in gear, say im going 55 gettin off the freeway and im in 3rd or even 4th gear, taking it down like that results it in smoking like all hell next time i hit the gas. there is one word for this.. GHETTO!!!!!!!!!!!!!! anyways, im thinkin head gasket but if someone knows or thinks better, than hit me back! thanks