Not that difficult of a job, didn't even follow a write up to do mine. It did take me two days since I painted the upper / lower intake and the valve covers. the two most aggravating parts was removing the coolant line underneath the throttle body closest to the firewall and removing the driver side valve cover. I found unplugging the fuel injectors, unclipping the wire harness at the back of the timing belt cover, removing the oil filler cap and wedging the valve cover under that harness at an angle towards the center the engine was the only way to get the bugger out. Oh by the way that plastic cover is a brittle piece of junk covering the wire harness there. The only thing I used off this site was the torque specs for the intake and throttle body, 13 ft.-lbs. Most of the nuts and bolts I removed where just re-installed in the spot they came from so I would not forget where they came from. Make sure not to drop any thing in the lower plenum and once you remove it cover the holes with a some clean rags. Also those two coolant lines on the bottom of throttle body will leak a good amount of fluid, have some rags ready and hopefully it will not be hot coolant like I experienced.... When it come to the spark plug grommets on the valve covers use a small and I mean a small flat head screwdriver and hammer. You will need to bend a metal tab up and out of the way and very carefully drive the screw driver in between the grommet and valve cover from the underside. Then just bend the little guys by prying the towards the center hole. Use a rubber mallet or a body hammer to beat the new ones in and bend those tabs back down. Just take your time, its easy to knock a little rubber of the outer edge of these things. When re-installing the valve covers I used a bit of black sealer ( p/n 00295-00103) from the dealership in the grove of the valve cover at the two half moon portions and in the corners of the half moon part of the head. would say if you have wrenching skills at all you can do it in 6 hours with just a few hand tools.
Tools:
10mm-14mm sockets
(2) 1 1/2" socket extensions
(1) 3/8" swivel
3/8" socket wrench
torque wrench with value as low as 10ft.-lbs. ( you can rent one and get an adapter to 3/8")
Phillips screw driver
small flat head screw driver
rubber mallet ( also use this to knock your valve covers loose, do not pry them off)
channel locks or pliers (for the snap bands holding most of the hose's on)
wd-40 ( makes it easier to get those hose's back on)
throttle body cleaner ( why not clean , you got it apart)
shop Rags
What to expect:
Frustration with the driver side valve cover
Frustration with removing all those rubber hoses, just twist them back and forth with pliers while pulling on them.
Coolant all over your garage floor
Its also recommended to disconnect the battery since you will be unplugging so much electrical. When tightening the hardware on the intake and valve covers work in a clock wise fashion from the center outward while only tightening the bolts in small increments to prevent warping. It may seem like a daunting task to preform, but all those hoses are only a certain length and most are bent in a manner that they will only go where they need to. All the plugs you unplug will only go back to where they are supposed to. Unless a hose tears on you, it will only cost you around fifty dollars if you have the tools and cleaner. Also to clean off the valve cover, save yourself the time... Use a pressure washer or take them to car wash and spend two dollars and spray them off, its a lot easier than purple power and rag.
Also you could pick up some mass air flow cleaner and perform the task as well...
4Runners.org - Cleaning Your Throttle Body and MAF
