I am new in the subby world and i am running into my first problem. I have a mechanical boost gauge installed and since the day i installed it (about a month ago) it was reading a strong 14psi at max and 20 vac at idle. I just changed the plugs with NKG and gaped them correctly. Every since the switch my car is maxing out at 10psi.. any ideas of whats going on? the car has 80,000 miles on it and had the original plugs before i replaced them.