Does someone have detailed procedure to reinstall EGR system?

not sure, but check @NutzAboutBolts youtube channel

 

Video #17 here:

Nutz About Bolts Prius Maintenance Videos | PriusChat

^ only, they do a coolant line disconnect that’s totally unnecessary (at throttle body). See second EGR link in my sig for more on coolant disconnection strategies.

 

He clamps off a couple hoses that aren't necessary, but I guess that's not a factor in reassembly.

One thing you might want to do is to squirt a little WD-40 on the threads of those two studs that connect the back of the cooler to the exhaust system. They spin in much easier that way. (Or do the same to the threads in the nuts welded to the back of the cooler, but no need to lube the nuts AND the studs.)

 

If you remove lower cooler nut and stud (in advance, and leave off*), the cooler is still stable/secure, and then you don’t need to remove the rear studs. It does bump a metal bracket above on the way out, but removing its hold-down bolt allows sufficient flex to clear. When those rear studs remain on they keep the rear gasket from falling, and aligned.

With the cooler removed it’s still good to remove the rear studs (off the car), to facilitate cleaning, avoid caustic solution getting at them. Do apply a thin coat of anti seize to the stud threads (or what have you) before reassembling, and reduce install torque** say 25%.

One thing that helps avoid confusion during reassemble, is to neatly lay out and label all nuts, bolts, studs and various small bits, in the order you removed them.

* Appreciate this might not work for pros, who could have an obligation to restore car to stock condition.

** Torque values in first link in my signature.

 

We don't re-install the "nasty nut" as I call it. It's redundant and almost impossible. Some of us remove that stud, but I find it's so close to stuff that I can't even get it out with a 1/4" drive ratchet & socket. So, for me, it's easier to remove the studs from the back end.

When I do an EGR (did two of then earlier this week), I use three magnetic pans. One gets all the fasteners from removing the cowling and wiper assemblies. One gets all the fasteners from the air box, intake manifold, throttle body, and EGR pipe. The third pan gets all the fasteners from the EGR cooler.

I also find that, if I'm going to need a restroom or snack/meal break, it helps to do that at the transition between each of those areas to make it easier to remember what's done and what's left to do.

 

Yeah last time I managed to have one left over cowl bolt. Looked it over about 4 times, could not find a place for it. Next time...