Ok, how will I ensure that the valves are closed on the cylinder that I'm pressurizing? On a side note, I'm ordering a new head gasket (Part# 12251-P01-004) because this one gave me my best readings, but I've been testing on a used one. Hopefully I'm just having a problem sealing the Y8 to the D16 with the '96-00 head gasket and the '88-92 will fix that issue.