EGR and intake service

You should be able to knock it out in a weekend, easy. Without any any parts preplacement, other than the pliable gaskets on the intake manifold. Even those would likely be fine, but might as well. Prepping helps immeasurably:

1. Amass the tools required.
2. Have both Oxi-Clean and crystalline lye on hand, for EGR cooler cleaning. Also have a white rubber stopper suitable for 21 mm diameter hole (smaller of the two EGR cooler end holes), it'll make caustic solution soaking the EGR cooler much easier. You want to start this soaking process as early as possible, it takes time.
3.In advance: remove the nut and stud on the lower EGR cooler bracket, and leave them off.
4.. Also in advance: remove, clean/lube and reinstall the nut/stud combo at EGR valve, ditto for the bolt going through EGR cooler upper bracket.
5. Remove the engine underpanel, and acquire replacement fasteners for any missing/broken. You may not even need to raise the car, but it's best to be ready.

Read through the two EGR cleaning links in my signature, plus the engine oil change link (has tips on engine underpanel removal). Also this:

Professional EGR Cleaning Resources | Page 9 | PriusChat

 

It's the nut and stud at the lower EGR cooler bracket. Visual aid:



1: EGR Cooler lower bracket nut/stud
2: EGR Valve nut/stud
3. EGR Cooler upper bracket bolt

Notes:

You will need an E8 Torx socket for the studs.

The nuts/bolts are 12 mm socket size.

The #1 nut is hard to get a socket and wrench on,, just due to all the stuff in vicinity. Forget what I used,, it did invove a swivel head ratchet, a possibly a 1.5" extension and deep socket. It's got to be just the right length, flexible to get through the forest of hoses and cables, and you're going mostly by feel

For the stud at same location (#1) I used a compact 1/4" ratchet, with the E8 Torx socket. It was a bear to break loose, and was stubborn all the way out. Could only accomplish one ratchet click at a time, and I was sweating that I would strip the head on it. Be very patient, and keep the socket firm and square on the stud head.

Lube the threads on everything when they're off (light/thorough skim of anti-seize compound, apply and wipe most off), and of course leave the #1 combo off, permanently:



^ leaving this off means you don't have to remove the studs at the connection to the exhaust manifold, and the gasket there will hang up on the studs, not drop down, and be MUCH easier to keep in place after the job, when you're reinstalling. When cleaning the cooler it'd be good to remove the studs, clean lube the thread and reinstall though, just to keep them from seizing down the road.

Note also the torque values:

The two nuts and one bolt are 15 ft/lb, and the studs are 84 in/lb (aka 7 ft/lb). A 3/8" or even 1/4" torque wrench is suitable for these.

One more: the "visual aid" above is a screen-grab from one of the pdf's linked in the EGR tips link in my signature.