Navigate the spider tunnel was a mission that Jak and Daxter completed to obtain a power cell in The Precursor Legacy. Jak had to force his way through the Spider Tunnel to get the power cell located away deep within.
When going to the second cavern with the Precursor robot in Spider Cave you'll have to walk down a bit of scaffolding, here at the bottom you'll have to turn around and head towards a pool of dark eco. Use the web trampolines here to cross it and enter a tunnel filled with many spider eggs as well as a yellow eco vent. It's important to note this vent will stay locked unless the Yellow vent switch has been found in Snowy Mountain.
Nonetheless it can be completed without the eco but it makes it considerably easier. As soon as you approach the eggs they'll hatch and not only that, many more hatchlings will come crawling out of holes in the walls. Force your way through to the end where a lone power cell awaits you in a (safe) bit of rock. Use the nearby blue eco and the launcher to launch yourself to safety.