Prius Gen 3 Major Maintenance: EGR, manifold, spark plugs, Oil Catch Can

Leave the stud for support.

Save the hard work for the lower cooler nut and gasket reinstall.

 

My stud got it's nut back.

I had to give it the ol reach around.

The way I drive, I need all my nuts in place

 

Update on some of the issues I had previously.

The P0171 system too lean code has been resolved;
This was a persistent issue even after a head gasket change. I was maxing out at ~35mpg on eco.

this is a pretty tricky umbrella code that covers a whole slew of possibilities.
So I started with cheapest fixes to most costly.
Inspected and cleaned MAF sensor -Nothing
New spark plugs. -Nothing
Then new fuel injectors. -Nothing
Finally I changed the fuel pump. -Eureka!

Back to 50 mpg. Code hasn’t returned in 2000 miles and counting.

Now I know a lot of people say that the fuel pump never has issues but that doesn’t seem to be the case; I’ve seen this issue on three different 2011 Prius’s now with the same code. I just changed my friend’s fuel pump who was up for smog test and it resolved the issue again.

So anyone dealing with the same code and frustrations, I completely understand the headache ; I suggest you go straight to the fuel pump replacement.

As far as the oil catch can goes: I installed the Ruien universal CC and have been using a copper sponge in it (yes, no fear of disintegration, they do not break apart). It has been pulling I would say about 50% of the oil going into the intake manifold. Still seeing a good amount of pooling. Wondering if anyone knows where to buy a nice circular bronze filter that I might stick in the baffling area. Otherwise I see a few low cost cans on eBay like the Mishimoto compact that already have a bronze filter installed. I believe these filter up to 40 µm which should pull a lot more oil from the air.

 

I changed the fuel pump on our old 2010, cause at some point everything fails:

What did you do to ur Gen III Prius today????

Definitely some sediment on the inlet filter.

But I'm sure the new owner was pleased with all the maintenance performed before his ownership began.

 

That's a pretty fair workup procedure given the code, and it did get you to the right culprit as long as you kept checking out the possibilities.

It's pretty typical really. Like any DTC, it means exactly what it means, but that's just that sensors are showing the mixture is lean. The computer has no way to climb out of its box and find out why that is, so that part of the job is for you. You have a decision tree that starts out "is the mixture ok and something wrong with the sensors, or are the sensors telling the truth and the mixture is lean"?

Going on down the sensors-ok, mixture-lean branch, you have all the possible reasons that could happen: clogged injectors, tired fuel pump, or air getting sucked in downstream of the MAF sensor where the computer doesn't know about it: flattened manifold gasket, leaky hose, hose not reconnected, any of that kind of thing. I personally wouldn't have included spark plugs in a mixture-too-lean workup. They can be suspects in a mixture-too-rich code (if the spark isn't happening, there'll be unburned fuel in the exhaust and the sensors will see the mixture too rich).

So that's not really the best lesson to take from your experience. The best lesson is to pretty much do exactly what you did (maybe minus the spark plugs): just one by one check off the things that could cause a mixture too lean.

The culprit is going to be one of them. When somebody else is getting the same code, the culprit can be any of those, not necessarily the same one as in your case.

 

Ok. My two cents. I used Nu Calgon evaporator (HVAC) cleaner on the cooler and the intake. Made the job quick and clean. Wear gloves, otherwise your skin will burn from the Nu Calgon; the stuff is strong. One thing that made the intake easy was the little brush that cleans the condensate trap drain on your for AC unit? Most houses have them somewhere around the inside unit. Did a great job the length of the intake EGR valley, and the tube handle went through the 4 small ports with ease.
I accidentally purchased two OCCs on amazon. Thinking I was going to return one, after reading that others were still having oil blow by, I went ahead and added a second one, mounted on the front cross member. I’ll let you know if it catches all oil. The OCCs were cheap, why not?

 

mmm cheap? Maybe 3? 4? or more?????

 

I'm running two OCC's, only they weren't cheap.

The second one actually picked up more, though mostly water.

 

No water = loss of power, as in water injection?

Posted via the PriusChat mobile app.

 

Whelp, I finally started to gather together everything needed for a dual oil catch can setup, moving the PCV valve up into a vertical position along the fuel line supplying the catch cans.

Also, got an EGR cooler off eBay, so I'll clean it up before taking everything apart for the catch can install. I figure it's worth it to make it as easy as possible to just swap in a precleaned one, rather than trying to get everything cleaned and reinstalled.

Now, I'll just be cleaning the intake passages, throttle body, and dealing with the PCV valve removal and replacement in a different position.

The YouTube video I saw, said that the OEM PCV location on the Gen 3 Prius is too close, and horizontal to the crankcase, so it passes too much oil vapor through.

The theory is that a vertically mounted PCV, away from the engine, will allow some oil to condense in the tubing and run back into the crankcase before going through the valve and into the intake.

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Hi!
I’m doing this cleanup this weekend. It’s going fine, I pulled out the intake manifold and EGR pipe and cleaned them up. The oil inside the intake is bad enough that I’m finally installing a catch can.

I’ve done everything from memory and it’s going fine. But I forgot one thing: What’s the sensor on the throttle body, and what do I use to clean it? I’ve removed it so as not to damage while squirting solvents into the manifold.

 

It’s the Manifold Absolute Pressure (MAP) sensor. I used CRC MAF (not MAP) sensor cleaner. Maybe overkill; the sensor looks pretty bullet-proof. Has to be, living in a swamp.

 

Is regular carburetor cleaner OK, or does it need to be MAP/MAF cleaner?

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DO NOT USE CARB CLEANER ON THOSE SENORS. Unless you were planning on replacing them anyways.
It will ruin them. Use the correct cleaner. I also read from several that alchohol (rubbing) is okay to use.
That's what I used because I didn't have to cleaner and search whether anything else was
safe to use.
But it's "best" to use the proper cleaner.

 

Got it. That’s what I thought. I have MAF cleaner.

 

Hello,

New user from Europe here. I am driving a 2015 Toyota Auris TS this is a station wagon variant of the 'iM' that you have in the US if Wikipedia is correct. Technically it is quite similar to the Prius 3rd gen, it looks like it has the same engine (2ZXR-FE) and hybrid battery under the backseat. Bought it two weeks ago with 160k km's (~100k miles) on it.

What i was wondering, i have read a lot about the whole EGR system clogging up, is this still relevant to newer Toyota hybrids like my 2015 Auris? I have read the diagnostics with a OBD-dongle (Viecar Bluetooth 4.0) and the Car Scanner app on my iPhone. It tells me the EGR monitor is 21.54 kPa. I am seeing quite lower pressures in the other thread, can i consider mine as 'clean' ? Would save me quite some time in disassembling half of the engine

P.S. Big thanks to @Mendel Leisk for the posts you have made. The attachments with technical info are hard to get and i found them very useful

 

Cleared the DTC (none found) which triggered the car to check this monitor again. Today i read 20.37 kPa.

 

Since I'm planning to do this maintenance (in two stages) I read/watch a lot of threads/videos and I stumble upon this (recent) video.

As a professional he replaced intake manifold and EGR valve with updated ones and did a software update too for those.
About OCC a comment draw my attention.

Q: Would an oil catch can be helpful on a vehicle like this?
A: Hi! It can but this engine already has an oil separator built in behind the manifold which is where the pcv valve connects to which does the same thing

So, cleaning stuff or replace/update?
OCC or not?

 

He’s completely wrong.
It’s easy to test whether a catch can will help: Install one and see if it catches oil. Lots of Gen 3 owners have done this and they caught a lot of oil.