ok what was the final say after 15 - 20 min did it stay at the 48psi or continue to drop?
Chevy Technician
GENERAL MOTORS MASTER TECHNICIAN, ASE CERTIFIED, 15 YEARS IN THE AUTOMOTIVE INDUSTRY
Brent, I finally fixed the problem went through the entire fuel system and everything checked out took it to the chevrolet Dealership and they told me that it was the spark plugs because the passenger side plugs were all fouled. My plugs weren't bad just fouled, So I cleaned them and I remembered that this truck has four O2 sensors two per bank. So what I did was unplug the upstream O2 sensor on the passenger side (bank 2) and the engine steadied up almost immediately then plugged it back in and my problem returned. One other symptem that was happening that I did not know was a symptem at the time was that there was a faint hint of black smoke comming out of the exhaust when the O2 sensor was plugged in and cleared up when the sensor was unplugged. So the remeady for this problem was a bad up stream O2 sensor on bank 2 (passanger side). Thank you for all of your help