I would recommend taking the vehicle into your local GM dealership to be diagnosed. They should be able to assist you further and have a plan for addressing the issue. If you have any other concerns, please feel free to private message me. Thank you.
Caron, GM Customer Service
Originally Posted by 99SLE
The tachometer in my 2007 Impala SS stopped working today. I also noticed that its not switching from 8 to 4 cylinder modes like it should. Well actually it doesn't shift to 4 cylinder at all. When driving down the highway at about 60 I am only getting 7 miles to the gallon. Does anyone have any experience with this, or any input at all? It is greatly appreciated