Periodically drive hard to reduce EGR clogging?

It's not easy to imagine how an Italian tune up would help with the EGR system, which turns off when you push hard.

 

You're a little late, hopefully ok.. Just from what I've read here, about how the clogging progresses and when head gaskets blow, 100K miles or 10 years (at the latest) for first cleaning, and 50K or 5 years thereafter, seems prudent. That the same as the Engine Coolant Change maintenance interval btw.

EGR info in first link in my signature.

 

The Prius EGR cooler is a heat exchanger with liquid water / engine coolant flowing through it. I don't see how you could get it hot enough to burn anything out of it, unless the liquid flow was first stopped or boiled away.

 

If you want a quick check of how late you are, you can ask the car how well EGR is flowing. Takes a matter of seconds, no dirt on your hands.

We have tended to see numbers around 21 kPa on a freshly cleaned system, decreasing as it gets occluded. Some hold that waiting for the P0401 code is waiting too long (that comes at around 1 kPa). I cleaned mine last summer when it was flowing around 10. (The number has units of pressure instead of flow for nerdy reasons of how the self-test works.)

Combine that check with a direct examination of the four small passages in the intake manifold. That's a quick easy check, and the built-in self test doesn't catch those, and unbalanced clogging of those may be the single most unhealthy thing that can happen to the EGR system, so it's worth a direct check.

 

my engine wasn't shutting down after warm up, so i tried the italian tune up and it worked. i have no idea what it affected though.

 

This is what an "Italian Tuneup" is:

"Italian tuneup is a slang automotive term for attempting to restore engine performance by driving a car at high engine speed and load. The term originated from Italian mechanics in the 1950s using this practice to burn off carbon deposits from the spark plugs of sports cars." --Wikipedia

 

Simplest Italian Tune Up would be to take a spin up a hill.

 

They should of called it the Pollish tune up...

 

i just took her out on the highway and kept flooring her in power mode

 

I run my car pretty hard. My oil was burning a lot in the past and after about 200k miles my egr was completely clogged so I don’t think driving the prius hard will help with the EGR.

 

Certainly the flow through the EGR doesn't correspond in any simple way to how hard you're pushing the car. It is used most at moderate loads, and turned off at high loads.

 

In other words: egr always on hence the clogging.

When we bought ours (at 130kmil) and headed home we had to do hours of highway driving. I was in other car following Prius and when it overtook a truck at highway speeds (my son said he was flooring it) very obvious black PUFF came out from exhaust for brief moment. Like diesel type of black smoke. I guess black smoke is often due to mixture being rich but in this case i believe it was some carbon coming out from cat or some other place. But not from egr.

 

Dont forget to change your coolants

 

For those of us without Techstream -- any idea whether the dealer would provide that data (for a fee, of course) during other maintenance?

 

You don't need Techstream, just a decent OBD reader and a free app (Torque, Car Scanner).

 

A decent 20 min freeway run (65 MPH) is good enough, IMHO....

REVVL V+ 5G ?

 

Ok, I'll bite: for what? To clean out the EGR system?

 

The 1.8L engine design is the problem and a clogged egr cooler is a symptom. As you noted, almost no other car has enough of an egr clogging problem to ever code. Occasionally they may experience a failed egr valve.

The gen3s and many other Toyota engines immediately preceding had oil burning problems caused by piston rings and poor cylinder cooling. The gen3 rings, pistons, cylinder cooling, pcv and egr systems were reengineered in 2016 with the gen4s Prius.

A preemptive rebuild that included a set of Toyota's recommended pistons and rings, along with a revised intake manifold, quality catch can and a machined head might save the catalytic converter down the road and give the engine another 150k-200k reliable miles. Some are simply replacing it with a newer gen4 engine, usually frankensteined with the gen3 intake and egr system.

Finally the egr is not absolutely needed in a good gas engine design. It does not exist in a gen2 or the newest Hybrid Max Toyota design. However a disabled egr is not a good option on gen3s.