2006 ss/na. Just replaced a new throttle body 3 days ago, because sometime when i changing gear, rev will shoot up to 3000rpm and stay for a while. After changing the TB everything is good for last 2 days. But today a new problem is happening again. Idle is around 1300 when coasting in neutral, it will drop to normal when come to a completely stop. It really annoying, i looked it up but i don't see a solution. Help please.