I know I'm waking up a old thread but hey why not! I have a 2011 Impala 3.5 and it's doing the slip bang shift into first. It has 113k on it. I've done 2 flushes since 2013 when bought it with 50k on it. Recently added a bottle of lucas and it's not as bad as it was but still there. For the most part it's pretty smooth when it's reached operating temp. Any of yall still driving with same issues or have yall got a fix and what was it? Kinda random but transmission was flawless until I had error message saying reduced engine power and had to replace sensor on wheel 5 years ago.