Things I would look for on a 2nd gen Tacoma.
The frame. Top issue.
All years of them were eventually covered in the limited service campaign for excessive frame corrosion and many of them got new frames. But not all, mine never qualified because it never rusted. So it's an annual ritual for me to clean and inspect.
Main spot to really look is on the inside of the frame near the catalytic converters, especially the driver side. They will rust from the inside out so if it the surface seems soft it's likely rusted inside pretty badly. This part of the frame is the boxed section and will require about a 4 foot long camera to see. No joke, the official way to check is hit the frame with the round end of a ball peen hammer.
They will also rust in the more normal areas for Toyotas, like in front of the rear spring hangers. Those are easy to see. Also check the frame up above the spare tire, good spot to judge overall condition.
If you're looking at a V6 with a stick shift the release bearing has a known issue where it'll squeak. This is due to the inner bearing race being steel will wear a groove in the snout extension it rides on, which is aluminum. When it makes noise it's mostly annoying. It'll squeak with the clutch engaged, the pedal NOT pushed, and will go away with the clutch disengaged, pedal pushed in. When it gets bad the clutch won't release smoothly. There is a fix using a Speedisleeve and custom machined release bearing. But the normal repair is to open things up and smooth the groove. This is fine but just isn't as long lasting. The 4-cylinder/5 speed didn't have this issue.
I'd check the rear driveshaft closely for play, the center carrier bearing rubber isolation on this wears fast in my experience and starts to wobble around. This will feel like a rear end clunk or pinion bearing going but isn't necessarily that.
If you're looking at 2011+ the secondary air injection system can be flaky. You don't want to ignore this long term since it can cause engine damage due to over rich conditions but it starts to show itself on cold starts. I don't have this system on my 2008 so couldn't say if it stores a code you could scan.
A high wear spot is the driver side support bearing for the inner side of the CV axle. It'll howl and eventually create a shimmy in the steering. You can grab the inside of the CV axle and see/feel the wiggle at the left side of the diff when it's worn. Kind of a PITA repair, probably 2 banana other than rigging up the puller to get the needle bearing out. I have a custom tool to do it.
