Im assuming there is a way to get the fuel pressure on a 2004 Colorado I5 3.5 other than the dealer. I asked my local garage to check it for me but they said they need a special gauge from gm to do it and I need to go to the dealer. Can anyone give me some insight into how to do it and what gauge system to get? I'm just trying to learn as much as I can with this truck since I plan on keeping it around for another 5+ years. Thanks in advance.