I have a 1998 Chevy 5.7 I'm having trouble with the idle control while going at a slow speed about 15 to 20 miles a hour the engine does not slow down when you let of the gas. It will keep going at the same speed even when you let off the gas but if you put the transmission it neutral it will immediately go to a idle. Any one else having this problem and maybe know what is causing it?

I have a 1998 Chevy 5.7 I'm having trouble with the idle control while going at a slow speed about 15 to 20 miles a hour the engine does not slow down when you let of the gas. It will keep going at the same speed even when you let off the gas but if you put the transmission it neutral it will immediately go to a idle. Any one else having this problem and maybe know what is causing it?

As far as I know, the engine will not slow down unless you put it into neutral or you press on the break..
But if it is acting unsually to you, it maybe the torque converter or transmission.

Being that said it maybe a good idea to the C/K forum. They will have more info for you on your pre-99 Silvy.. Good luck to you