Of late I'm noticing that my vacuum reading at idle (760-780 rpm) has gone down to 13 Hg. From the archives, I found that 20 at idle and 17 with ac is normal. So do I have a vacuum leak? Or is my gauge off (autometers are not accurate)? I'm noticing that third gear max boost is limited to 18 psi only, earlier I could take it up to 20+; are these related? If there is a vacuum leak, what problems can it cause? Can my local technician smoke-test it or do I have to take it to the experts at 3zero3 or Avalon in Colorado?
Also, what is heat-soak? I've noticed that when I'm driving around in town doing about 40-50 mph, the car is running fine but about two hours of freeway driving at 85 mph later, when I'm back in 30-50 mph driving mode, the car is not that rev-happy-I mean I really have to flex my right foot (especially in the lower two gears) to get the car to do what it was doing before the 85 mph highway run! Is this normal? Appreciate any help and TIA!!