Reach the end of Lava Tube was a mission that Jak and Daxter completed to obtain a power cell in The Precursor Legacy. Jak had to continue his quest to stop Gol and Maia from completing their goal, to do this he crossed the dangerous Lava Tube to reach their citadel.
The PlayStation 3 and Vita versions of this mission are related to a trophy named "Zoom, Zoom, Zoom!", completing this mission will reward you with a bronze trophy.
The last mission with the A-Grav Zoomer as well as the longest. It's similar to the Fire Canyon in that the Lava Tube once again introduces the heating element where you'll need to stay off the lava and use cooling balloons to cool the zoomer down.
The first part is pretty standard, avoid falling into the lava and try to stay on the mostly dried-up spots. Eventually you'll reach three yellow eco vents and enter a large half-spherical room with in the center a big machine with five 'power spheres' spinning around in a circle. Use the couple cooling balloons around the center to cool yourself and pick up any yellow eco here as well which needs to be used to shoot down the spheres.
A door will open leading into the next section; a dark eco factory of sorts, as well as smaller sections of racing over metal roller coaster-like rails. The rails-sections are pretty confusing and due to their small size it's difficult to stay on them. While this is arguably the most difficult part of the level, there's no danger of overheating here so it's recommended to take it a little slower to avoid dying.
The dark eco factory sections on the other hand are pretty straightforward with the main obstacles being dark eco mines and large containers being moved from side to side every so often. Periodically you can yellow eco vents which should be used to destroy the mines (the containers are more durable). Slow down when getting too close to either of them though since touching these means instant death. The containers will show a gap every so often which has to be used to get past.
After these sections you'll reach the end and with a long jump ending up at the trans-pad with the power cell.