I have a 2006 G6 with a 2.4 litter and 4 speed 4t45 transmission. The problem I am having is my transmission will not shift at high RPM (5700-6000RPM). If I am on the highway and floor the gas pedal, the transimission will shift into lower gear without a problem. The problem occurs when the RPMs get up to around 5700-6000 the trans will not shift into the next gear. I will hit the Rev limiter and my motor starts to misfire. All this occurs while the gas pedal is floored. If I let up some on the pedal it will shift to the next gear. As anyone else encountered this problem? Does anyone have any suggestions to resolve this issue. Thanks for any advice.