2010 Prius with EGR CIL 155K

Using Techstream, or another scan tool with active tests, what happens at idle when you start advancing the valve opening one step at a time? What step can you get to before the idle becomes rough (if it ever does)?

The repair manual gives some precautions for this test, like warming up to 75°C or higher, not playing with EGR openings above step 30 or for more than 10 seconds, and being sure to return it to step 0 when done.

Are there any untold stories about the wiring to this valve? There were some threads where people did engine swaps and exchanged a couple pins at the EGR valve connector, which would make the valve not work. Any chance something like that could have happened?

 

You’ve cleaned: EGR cooler, valve, pipe (between valve and intake manifold) and the intake manifold EGR passages?

If no, I’d address what’s missed. If yes, try changing the valve.

see first link in my signature too.

 

Googling, they point to MAF sensor and hybrid battery fan respectively. The MAF sensor does need to be disconnected when accessing EGR components; you’ve checked it’s connector? And the fan condition?

maybe too: codes can persist for the next few start ups, then go away??

All I got.