Improve performance

Take the pipe you have marked as cleaned off, then remove the 2 bolts that are holding the egr valve onto the cooler off.

Did you find a lot of deposits in the egr pipe you cleaned and that's why you want to investigate the egr valve? Or is it throwing a code?

 

The attached document shows removal and install of the EGR valve and associated cooler component. Also attached is a pdf for removal of wiper motors and windshield cowl, necessary for cooler access.

I think if you are able to remove the EGR valve for cleaning, you can then look into the opening of the cooler, judge if you want to remove and clean, or just replace, if it's hopelessly clogged.

There's also a good video on the wiper motor and cowl removal procedure, in the spark plug video by @NutzAboutBolts , pinned in the 3rd gen maintenance sub-forum.

 

I would clean further downstream of the egr pipe to improve performance. The inlets from the egr into the intake manifold have been known to clog. If you are noticing hesitation, rough idle or poor transition between engines, I would look to clean the intake manifold, particularly the small inlet ports. While doing that, you can clean the MAF sensor, throttle body and potentially the pcv valve.

Good luck.

 

Hi Tariq!
If you clean the throttle body of the Prius, when you look down inside the throttle body, you will see oil. That is normal. If you remove this oil, it will just come back. It is because the engine's Atkinson cycle design keeps the intake valves open during part of the compression stroke, which will blow some oil back into the intake manifold, which you will see if you look past the throttle body butterfly valve.
I am telling you because, when I saw this oil, I was really worried, but it turns out, it is normal with this kind of engine.

 

Basically the EGR circuit can be royally clogged all the way from the exhaust manifold to the intake manifold, lol.

 

Is have done the whole circuit and it can get clogged with carbon deposits. I bought a spare egr valve and cooler from the salvage yard and it worked out well. IMO, the ports on the intake manifold from the egr are a major issue that could lead to the cylinder misfire (assuming you have replaced the plugs, have the correct gap, and do not have a coil malfunction).

A good pipe cleaner or small nylon brush gets those small inlets clean and airflow back. As @Rebound said, the Atkinson engine naturally seeps oil into the intake and the egr inlets are on the bottom of the manifold. So guess where a place to collect would be before it gets to the throttle body.

Keep us posted!