Was the 2nd owner of 2000 3.4L 4Runner (2wd). I bought it with 40,000 miles on the odometer. Was still running/pulling great with over 280,000 miles when it was rear-ended & totaled because of some woman in a Mercedes dealership courtesy vehicle who had turned around to yell at her kid while driving. Really crappy thing is that she was driving a courtesy vehicle because her own vehicle was at the dealership getting work done because of another accident she had caused...
Preventive maintenance included, changing the oil & oil-filter every 5,000-ish miles with synthetic (usually Quaker State because it was the cheapest name-brand full-synthetic on the shelf unless something else was on special & regular old Fram oil filters unless anything else was on sale/special). Changed the timing belt, water pump, tensioners, & coolant every 100k. Changed the air filter every 2 years (CA smog test every 2-years so just did this prior to every smog test). Changed the spark plugs every 4 years (before every-other smog test). Changed the brake pads and resurfaced or replaced the rotors whenever needed. Changed the upper & lower ball-joints at 200k. And rotated & change the tires before they started to look like slicks.
Corrective maintenance included changing the valve cover gaskets, each side twice, both times lasted long, but they eventually got hard/brittle and started to leak slowly. Replaced ALL of the vacuum hoses in the engine compartment. One of the original larger diameter vacuum hoses developed a small tear just out of view, and I just about went nuts trying to figure out what was wrong with the truck... The CEL code suggested it could be the MAF sensor or dirty throttle-body so naturally I assumed the harder more expensive stuff to tackle first (clean then replace MAF and clean the throttle-body), but it turned out to be a stink'n vacuum hose, so I changed all the hoses. Changed the O2 sensors once (can't remember which went bad, but changed'em all). Did the Tundra front brake upgrade. Got a lot of use out of the truck to tow the desert toys through the SoCal mountains on weekends during the desert season and the stock sized rotors would warp pretty quick, so the thicker Tundra rotors and more brake pad surface area (larger pads) helped stop the truck with less effort & I got less rotor warpage. Had the front wheel bearings changed once (can't remember the mileage). Had the drive shaft u-joints replaced twice (they probably would have lasted longer, but I never hit them with a grease gun). Changed the catalytic converters for the last smog test right before it got rear-ended. I pulled those new cats off before the tow truck came to haul the 4Runner away, thinking that I might get another 3.4L Yota.
Aside from the high mileage, the truck was in great shape, and the insurance company actually surprised me with their pay-out being more than I could have ever sold the truck for. I used the pay-out toward the purchase of a 4th Gen 4wd 4Runner (got tired of stressing out with the 2wd when pulling the trailer through soft dirt & sand). Now I'm taking just as-good or better care of this one!