EGR valve

I just wanted to say that I am very happy to be member of this forum...
As planned before, these days I did an intake manifold cleaning...
Now, the symptoms are gone.
I made a calendar event to do it again after 50000 km.
So, here are some pictures, but let me explain what the real cause was, (with mine words, I am not a mechanic, sorry).
I cleaned throtle body (not necessary, I think), the PCV valve (very bad condition, full of oil an residual things and intake manifold, but not in the big holes (of course, it was some contamination there), but the real problem for my issue was in the little channels from intake manifold...
I mean, from the side of intake manifold connected to EGR...
The exhaust is driven through EGR valve and through these little channels in intake manifold...
Maybe I am not so clear, but if somebody needs to know more, just ask me and I will answer,
The idea is that my issue has gone, now the engine is running in factory parameters...

 

We're very happy to have you here!!
Excellent post!!

Good luck with your car.

 

@GabrielD yes, the intake manifold is the last portion of the EGR path, and if not cleaned you will still have blockage.

Have you also cleaned the EGR connector pipe, valve and cooler? These 3 names are maybe not exactly what Toyota calls them, but descriptive. These 3 pieces, from left to right:

 

Yes, I cleaned it all... see may early post, or here are the pictures...

 

I would love to understand how a clogged EGR cooler can overtime damage the head gasket.

 

The difficulty isn't finding a thread here on PriusChat where that topic is discussed; the difficulty is that there are so many of them. In the most recent one I happen to remember, you could start at this post and read on down.

Spoiler: there's a very vocal school of thought here convinced of that causal connection, but it's not unanimous.

There's a related, not quite identical, concern about clogging of the four separate EGR passages within the intake manifold. That could be worth keeping an eye on, by direct inspection, because when those clog by different amounts, the car's built-in monitoring of EGR flow can't detect that (it only has one sensor for overall flow), and there is a less-speculative story about how damage can result from those flow differences.