[TRE Cup]

Since there tends to be carbon build up on the plugs, a tip before doing the test is to crack the plugs loose, reconnect the cables, start the car up. Rev it a few times to blow off the carbon. then do the test.
We have found that if you don't blow out the carbon, it can get caught between the exhaust valve and seat. Obviously this gives you erroneous readings

Not sure where the leakage is coming from ? Wet your finger, place it in the exhaust tip, oil tank opening, or the opened intake ( push the gas pedal down) . Whichever area (could be more than one ) gets the finger cooler is the problem area