Gen 4 EGR cleaning at 360,000 miles

Wish there was a super-like button.

@Raytheeagle had similar “fun”, extracting EGR components on his prime.

Sounds like they sorted out the carbon clogging. A stark difference from gen 3.

The prodigal son parable comes to mind.

 

Yes, that would be good. Gen 4 surely has the same built-in emissions monitor that you can ask about your EGR flow score any time you want, same as Gen 3. Starting a similar Gen 4 forum thread with some mileages and flow scores would be a way to get some very useful information, with a lot less trouble than bungeeing the inverter out of the way.

My guess is that there will be some Gen 4s, maybe with fewer highway miles, that might show worse flow scores than this one did. (For that matter, it would have been nice to know the score for this one!)

 

This thread is maybe more interesting to third gen owners: 4th gen Prius, with all the lessons learned from third gen EGR, 360k miles, never had a cleaning, next to no carbon, and no head gasket problems.

a couple of cold comforts:

1. the #%*!# 3rd gen EGR components are easier to access (amazingly).

2. our exhaust heat recovery components aren’t having coolant incontinence issues.

 

Gen 4 cars have a different EGR system because the auto industry was researching a different EGR chemistry during the years Gen 3 was in design and production, and there are journal papers on the new chemistry, "catalyzed EGR", that were published during that time. Gen 4 uses that newer approach, which hadn't really been commercialized at the time Gen 3 was in design. Taking the gas from after the catalyst changes its chemical make-up and changes its effects on combustion, as the journal papers describe. And the components for catalyzed EGR have to be larger, because the gas from after the catalyst is of lower pressure. Everything must be proportionally larger to get the right flow.

So there is a good deal more to the change between the Gen 3 and 4 equipment than just "lessons learned from third gen EGR".

As this thread's in a Gen 4 forum, one hopes it'll stay interesting to Gen 4 owners, who can use it to collect their own data on how a wide sample of their own cars are doing (not all of which will have put on 360,000 miles in a handful of years).

There won't be anything wrong with us Gen 3 owners peeking in, but we already have our own thread for Gen 3 mileage and EGR flow reporting. We can leave the Gen 4 folks a little space to have their own.

@jerrymildred, what was the year of this 360,000 mile car?

 

Yessir...

 

most gen 4 owners haven't a clue, unless they owned a defective gen 3

 

3. The 3rd-generation engine coolant pump is less difficult to replace, as I understand.