vacuum leak or fuel system?Long

[richie]

I got a vacuum gauge today and hooked it up to my upper intake and then all other vacuum line and the psi was around 17 on all the lines.When the engine was idling I could hear a hissing sound coming from the right side of the intake.I used my sethescope and found no leaks.Then I sprayed come carb cleaner around the intake gasket and intake bolts and around the fuel injectors.The idle didn't change at all.The hissing sound comes and goes,it's not constant.A couple months ago I checked for codes and got a egr postion sensor code 34 if I can remember.I disconnect the egr vacuum line and plugged it and the other line.Then drove the car and it ran real strong on the freeway.