Do all Gen 3's (2010-2014) need EGR Cleaning?

Grit · Nov 2, 2023

Nick Seifert said: ↑

I thought i'd add my own experience with my 2012 Plug in Prius, 160k miles on the odometer. I purchased the car used with around 80k miles on it, decent service records, but the EGR system was not on the list of repairs AFAIK. Knowing the issues and failures a clogged EGR system has caused in many Gen 3's, i figured mine was far overdue. Before undertaking this work, i did check that the EGR valve TSB (T-SB-0027-16) sticker was not present under the hood, and i confirmed that my VIN is in the affected range. I have not ever had the P0401 codes, or any of the engine shaking reported by others. My goal was strictly preventative maintenance, i'm hoping to keep this car a lot more miles!

On disassembly i found the EGR pipe was pretty clean, only a thin layer and some chunks of carbonized oil. The inlet from the EGR valve (to the EGR pipe) had a similar crispy thin layer, but not obstructed. I didn't touch the EGR valve itself, or cooler, just the EGR pipe forward. The intake manifold did have maybe 1-2 TBSP of oil below the throttle body. The throttle body had a fair amount of carbon on it. The intake manifold itself, and the intake ports in the head, were similar to above and had a thin carbon layer, but no clogs. I inspected and blasted the EGR ports in the intake manifold for each cylinder, and confirmed that all were free and clear enough to circulate gas.

So basically, on my 160k 11 year old Gen 3, which i don't believe has had any prior EGR service, it was totally fine. That said, your mileage may vary of course, along with driving style, trip duration, etc. I'm glad i found no issues. I only wish i had bought two cans of manfold cleaner, instead of one! I did not get too crazy about getting the intake manifold spotless, but did give it some blasts of cleaner, a bit of scraping and wiping, new gaskets, and put it all back together.

Will i do this every 50k miles? maybe... maybe not. I will probably do it at least one more time, and see if it continues to NOT be a problem for me.

FWIW, i'm religious about oil changes every 5k miles, and use full synthetic. I have no oil consumption at all.
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I wonder if being a plug in model has less ice up time. Extra curricular reading to go.

Nick Seifert · Nov 12, 2023

Grit said: ↑

I wonder if being a plug in model has less ice up time. Extra curricular reading to go.
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Yes, for sure. I'm diligent about plugging it in, but do have an occasional long commute. I average around 15%-20% of EV only.

Nick Seifert · Nov 12, 2023

ChapmanF said: ↑

Did you ask the car for the EGR flow test value, either before or after doing your work (or, ideally, both)?
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I did not do this before the cleaning, but below are a few results from after. looking pretty high, i'd say, this is using the Car Scanner Pro app, and the "noncontinuous monitors" page. pulled on different days. I'll post over in that thread you linked as well, ChapmanF.

mp98103 · Apr 25, 2024

rjparker said: ↑

Depends on your vin. After a certain vin you may have the improved pistons and rings. Which is important because they vastly limit the hydrocarbons flowing through the exhaust and into the egr cooler. Revised pistons and rings also slow down blowby that enters the intake manifold via the pcv valve.

While it is true the egr and pcv systems were a design fail on gen3s, limiting oil and combustion blowby in those systems has more to do with carbon accumulations than preemptive and presumptive removals and cleaning. Same goes for catch cans. Carbon accumulations on engines from 2010- mid 2014 does not stop simply because someone improved the flow in the egr system at 100k miles. The low tension rings and pistons with poor oil passages are still in there doing their thing clogging up the whole top end twice as fast since they are worn. As stated above, my egr took 100k miles to clog the first time and only 50k the second time. Resolving the root cause is always the best plan; attacking the symptoms just gives the diyer warm fuzzies.

The theory that cleaning prevents head gaskets has proven false many times but the claim still circulates on Priuschat and nowhere else, especially not with professional Toyota mechanics.

On the other hand, in a 2014 you could have the bad rings from the factory, so why not go with cleanliness is next to godliness and who does not want to be next to Aaron Rodgers. Just don't drink too much of the psychedelic koolaid he suggests or think cleaning egrs on 2010- mid 2014 Prii is some sort of magic bullet.

Updated pistons and rings in 2014 Prii. Use last six digits
View attachment 231852
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Ok, so just to be sure, a '1' means the 2014 Prius has the updated rings just like the 2015 and older ones do, yes? TIA.

rjparker · Apr 25, 2024

mp98103 said: ↑

Ok, so just to be sure, a '1' means the 2014 Prius has the updated rings just like the 2015 and older ones do, yes? TIA.
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No.

A 1 means your car came from factory 1. You then use the following sequence number.

If your sequence number in your vin is higher you have the updated parts.

If that does not make sense just provide your vin and we will read it.

Do all Gen 3's (2010-2014) need EGR Cleaning?

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Do all Gen 3's (2010-2014) need EGR Cleaning?

Grit Senior Member

Nick Seifert Junior Member

Nick Seifert Junior Member

mp98103 New Member

rjparker Tu Humilde Sirviente