Backfire!?

[MrHaTcH89]

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

 

[omega11855]

the reason your idle goes up and down like that is cause a sensor is unplugged (i am almost positive) its a colant sensor (if i am correct actually not positive what the sensor is for ) but its round and on the left side of the head by the distributor check to see if its plugged in if not plug it in your car should then idle normally

 

[tdehnel]

Strange. I get that exact idle problem you mentioned sometimes with my Turbo B16. Any thoughts on why this could be happening to both of us? Mine seems to do it more frequently when it's cold out, or after running it harder than normal.

 

[MrHaTcH89]

did u mean coolant sensor when u said that?? also where exactly is it located??