Beware the average user trying to clean EGR pipe and cooler....

Well, looks I gave folks something to talk about at least!

-- I've only been doing 12k OCI since Mobil 1 starting putting it on their jug as allowable. Previously was 7.5k for much of the 2011 life. Since its up in the air and the bottom shroud is off, I'll be doing a 9k change tomorrow. And the plan for a 15k change never materialized, as that was the oil that is in there now (Mobil now has 15k on the jug, at least some of them).

-- I did NOT do the intake manifold. My EGR cooler was coated in a light layer of browning soot. No oil. I could see light through it, and a farm boy test of blowing through it did not reveal a lot of resistance compared to the clean one.

--The clean one, off ebay, was truly clogged on arrival. I used stoppers and Drano to clean it out. I highly recommend good old sodium hydroxide. Get a generic. Put a stopper in. Fill it and walk away for a day. Couple repeat, paired with some piano wire, and it was spotless.

-- I did get it back together this AM. Including the blasted lower stud. The flanged nut happens to be the same diameter as my deep well socket. So I taped the nut in place with masking tape. Taped a short extension in place too. Then using the really narrow view you can get of the stud (requires a good light and some contortion tricks) I was able to guide my socket with taped nut to the stud, get it started, slip in a ratchet and tighten up. Remainder of re-assembly was reasonable. Rear gasket stays in place pinched between the exhaust manifold pipe and the cooler. Align the holes with small drift punch (tapered punch).

-- Waterpump was easy compared. Several youtube vids show removal of the bottom bolt only from below. IMHO, one should take the bottom 3 bolts out from below. Was easier. But as noted, I have large hands and from above, was not easy to get in. Put in a new Aisin/Toyo waterpump. Life is too short for cheap parts.

-- I bought no new tools, except for finally a magnetic 9/16" spark plug socket (did those too). Used some that have gathered dust lately. For the rear EGR cooler studs, I have a threaded rod ratchet. Its got a hole through it, so you can deal with infinite length of bolt.

I'll have to see if my scan software will measure the EGR flow. I own two gen 3 prius and neither has given trouble. Family wants both to run for a long time. I remain somewhat skeptical that all this trouble is needed, especially in a vehicle with no problems and no history of problems. My old water pump looks so good, I 'm tempted to sell it on ebay. Probably a 10 year old Aisin/Toyota pump that looks find and has never been run dry, is still better than a new chinese knockoff.......