Obtain 13/32 Drill bit
Add some oil to drill and hole and drill hole carefully and straight as possible.
Obtain a taper tool (hardware store or harbor freight)
Add a slight taper to the edge. Use oil to keep for smooth cut surface.
If you don’t have this tool, you can alternatively use a larger drill bit and slowly just add an edge to the hole. This is to allow the rubber seal an easy way to insert without breaking the O-ring seal on the sensor.
Obtain a Tap kit for making an M6 thread bolt hole. These combo kits are available at most auto part stores for repair jobs.
Insert the Map sensor and mark the center of the hole with the drill bit.
YOU MUST ENSURE THE HOLE IS CENTERED. YOU CAN BREAK THE SENSOR IF NOT ALIGNED PROPERLY AND FORCE THE BOLT TO ALIGN THE SENSOR INTO THE HOLES.
If worried about alignment, go with an M5 bolt instead and this will allow some space and room for error.
Remove Map Sensor and carefully drill the hole centered and straight.
Below is an example of the drilled holes.
Find your Tap Tool and add a little oil to the thread cutting tool.
Carefully tap the hole. Let the tool do the work. Should cut really easy. Always use Oil!!
Sample of the finished process and vacuum boost fitting reattached to manifold.