My 06 Cobalt ss/sc was surging during idle... I cleaned the throttle body and it stoped the surging. But now the idle is all wacky. Coasting, coming to a stop the rpm's are at 2000...then when I stop they will drop to where they should be. Also, when I shift the rpm's will delay to drop. Anyone have any clues????? Help me out.
Thank you.

 

Coastdown is a little high but nothing abnormal.

Shifting could be you keeping your foot on the throttle a split second past the time you engage the clutch.

 

naw cuz i take my foot off the gas completly and clutch it....and it still doesnt drop fast like it did.
Thank you

 

Clean your t/b
Check your plugs and regap if needed
Disconnect your battery over night

 

ok ill do it all