To be sure, I recommend:
* Checking your owner's manual: This is the best place to start. A diagram may be included.
* Consulting a repair manual (like a Haynes or Chilton manual): These manuals often have detailed diagrams showing the location of all components, including the vacuum canister.
* Using an online parts diagram: Many websites like AutoZone or Advance Auto Parts allow you to search for your specific vehicle and view diagrams of the engine compartment.
Searching for "1998 Pontiac Transport vacuum canister location" with images on Google or YouTube might also be helpful. Remember to always be careful when working under the hood and disconnect the negative battery terminal before starting any repairs.