you will need to call a Pontiac dealer and get an activation code, because of the anti-theift system.
For a Pontiac Montana the battery is a group 78. Follow this link for dimensions.http://www.rtpnet.org/teaa/bcigroup.html
Pontiac Montana was created in 1999.
Begin by removing the positive cable from your battery. Remove the cables from the front of the starter. Remove the starter retaining bolts. Reverse the process to install your new Pontiac Montana battery.
Cam sensor location 02 pontiac montana 3.4
alternator
215/70R15
with explosives
p134
you will have to pull your radio out of the dash to be able to look at the model number and/or serial number of your radio. Call a local Pontiac dealer and they can give you a code to enter when you turn your radio on after changing your battery.
drums
Connect positive to positive post (red) on the battery and connect the negative to a place on the engine away from the battery.
You can find the oil pressure sensor for your 1999 Pontiac Montana on the front of the engine. The low pressure oil sensor will be just below the left cylinder head.