Is telling people to clean the EGR system a prank?

it's definitely an issue, but hard to quantify, as there is no proper testing data to look at. so people have different experiences, and it's unknown as to why that is.
did you clean the tiny intake manifold ports? they are very important.

 

Did you happen to take before and after flow measurement, as seen in this thread?

That's one way of approaching the "was it necessary" question with a bit of hard data. It's also helpful for other people to see if you add the before/after numbers to that thread.

 

Not a prank—cleaning the EGR and intake is a smart move at 107k miles. It helps prevent head gasket issues and rough starts. Since it's already apart, good call on replacing spark plugs. Also check the PCV valve, clean the throttle body, and inspect the intake for oil. You’re definitely on the right track!

 

I asked similar, again jokingly, about physicists and their "string theory". A "fly on the wall scenario":

A meeting of physicists, all file into a conference room, close the door, sit around a table, and the chairman asks: "are we all physicists here? Good. Ok, we can drop that "string theory" nonsense." Chuckles abound...

But EGR cleaning, not so much mirth; see attached.

It's not that hard. There are tactics that help:

1. Remove EGR cooler lower bracket nut and stud, in advance of the "big day". This can be done with out removal of anything else, and can be left off permanently. Besides getting a troublesome fastener out of the way, it also means you can leave the cooler's rearmost pair of studs on. This saves time, and ensures the gasket there won't drop down as you pull the cooler out. Also helps to align when reinstalling.

While you're at it, remove the EGR valve's lower nut and stud and upper bolt, put a light patina of anti-seize and reinstall (see top link in my signature for torque info; on a phone turn it landscape to see signatures).

2. Assuming you're not doing a coolant change at same time: o avoid coolant spillage when removing EGR cooler, preemptively drain two quarts of coolant from the radiator drain spigot, into a clean container (return to reservoir after completion). Note: you do NOT need to remove the throttle body's coolant hoses.

3. Deal with the EGR cooler first. Get it out, one end corked and propped up in a corner of a laundry sink or rectangular bucket, with a carbon-eating solution. For light accumulations oxi-clean versatile stain remover will do, or escalate to lye.

4. Stay organized with everything you remove, lay stuff out sequentially, use labels.

5. Budget a weekend for this; you don't want to rush.

6. Pay very close attension to the direction the egr's metal gasket's central holes "dimple". Most go one way, one the other way. I've got a pic somewhere, but most expedient is to just note during removal.

 

Yeah that's 200kish. Keep in mind though: the EGR cooler namesake is not trivial, and even a modest coat of carbon, while not impeding flow, is reducing the cooling ability. Too, while overall clogging may not be bad, the EGR passasge at cylinder one on the intake manifold will lead the pack in clogging.

 

Not everyone has Techstream. AUTEL AP200 or other scanners can extract this data from the ECU?
Or only a step-by-step test for the EGR valve?

 

The scan tool has to be able to get "mode 6" monitor test results. That is a standard OBD-II feature so many scan tools can do it, AP200 included. The thread linked above has examples contributed by a lot of people with a lot of different scan tools.

On the AP200, as it is a standard OBD-II and not manufacturer-specific feature, you find it in the "Eobd" screens of the app, not the Toyota ones.

 

I'll try to check this on the Prius V.
The EGR system is the same.

 

Car Scanner easily reports the noncontinuous monitors. My v routinely is around 20.8 kPa but varies between 19 and 22.

cat and egr