Also.. it's a 2006 GTP
They need to pull the tank again ..either the float came loose ( which is very easy to happen) or as mine was the sending unit was bad on a new pump and I changed out the whole unit under warranty. Also spend the money and buy the ac delco pump oem..its not a easy job. Did mine 3 times before I got it right..exact same issues as you..good luckHi so had to have my fuel pump replaced, when he finished my gas gauge was reading where it was before he did the job yet I ran out of gas. When I got a gallon in it to start it & get it to the gas station it read low fuel which it should have. I filled my tank & it still says low fuel with my fuel light & engine light on. Ran for codes it had many. Had them cleared & both lights came back on. Now it's reading for fuel level sensor. Where do I start to remedy this??