Cam shaft sensor

Hello, I’m Pete from the Car Genius team at RepairPal. Without knowing the engine size in your 2008 Chevrolet Impala this does make it difficult to look into this for you to let you know where the camshaft sensor itself is located. I can say that for most models this sensor is usually located at the front of the engine towards the top or middle areas of the valve covers, cylinder head, or timing cover. If you are able to provide the engine size information this will definitely help! If you are able to let us know which engine your Impala has in it just give us a call at 877-913-1554 where we will be happy to further assist!