One problem related to tank mounting has been reported for the 2001 GMC Sierra 1500. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2001 GMC Sierra 1500 based on all problems reported for the 2001 Sierra 1500.
The fuel gauge began jumping from full to empty regarless of the actual amount of fuel in the tank. I took gm's recommendation to put their fuel system cleaner into the gas tank to clean the contacts on the fuel sending unit. Approximately 6 months later, the catalytic converter plugged to the point that the vehicle would not run and it had to be replaced. Now told that only way to fix the fuel gauge is to pull the gas tank and replace the sending unit. Should be a recall for this faulty sending unit and the "quick fix" that many people probably try. Approximately $400 to fix sending unit because it's built into the gas tank, and approximately $1000 to replace the catalytic converter.