Hey guys im new to the forum but Ive been reading quite a bit. I have a 96 suburban and for the past few weeks it has felt sluggish. It doesnt throw any codes and it doesnt really hesitate or miss that i can tell. It just feels like I am pulling a trailer or something. Seems like i have to lean into the throttle more than usual. I do my own work but I just couldnt figure it out so I took it to the gmc dealer to have them diagnose it. They pressure checked one cat and it checked out fine but they were unable to check the other one because the o2 sensor was really frozen in there and they were afraid to break it. It is there opinion that my fuel pump is bad. The sheet that they gave me says "after priming fuel system could only achieve 57psi key on and engine off. spec is 60-66. for sequential fuel injection." My question is...could that little of pressure difference cause this problem? i would hate to drop the tank and find out that this is not the problem. Also as a side note, I have replaced the spider assembly a few months ago with the updated one. It ran great right after the upgrade. Thanks guys!!