Pontiac Montana was created in 1999.
In exhaust pipe before catalytic converter unscrew to replace
Cam sensor location 02 pontiac montana 3.4
Should be located at the top of the starter Remove starter Remove 2 screws at side of solenoid Twist (spring loaded) to remove
For a Pontiac Montana the battery is a group 78. Follow this link for dimensions.http://www.rtpnet.org/teaa/bcigroup.html
it would be best because you could tear the old ones while removing them.
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.
Pay a mechanic to replace it