What can cause a steady clicking noise from rear of vehicle

Hi this is Dusty, I'm one of the auto experts on RepairPal's Car Genius team! Sorry to hear about the nuisance noise with your Tahoe. A fuel pump could be the source, though they're generally submerged in some amount of fuel, and encased in the tank, both of which tend to dampen sound. Determining what's causing it will require a firsthand look, or more accurately a listen to your vehicle. The good news is that it's easily duplicated so an experienced, qualified technician should be able to make quick work of locating the source of the noise, as well as provide feedback on resolving it. If you have any other questions or would like to help with finding a RepairPal Certified shop in your area, give us a call! 877-913-1554