Still P0401 after cleaning egr !! should we drive it?

We agree: in #179 I said there are multiple full rotations. (That was an edit; before the edit it said "there's more than one full rotation". I made the edit to be even clearer, but it meant the same thing.) That's why the ramp/stop can't be taller than it is: it has to hit the nib on the final turn to fully closed, but has to be out of the way as the rotor passes the same position on other turns.

The 155k valve I opened was in generally fine condition in there, other than the mashed ski jump. Kind of a shame.

 

Exactly why I'd like to figure out to fix this. I hate that a little piece of plastic determines the fate of a $100+ part.

 

Ok I'll apologize - earlier I said "if the EGR is going to fail it would be the ramp/stop"

After cleaning the stem and getting the valve to open smoothly and easily, I'm no longer getting P0401. My guess is that the "sticky" EGR valve was throwing the code, not necessarily the ramp/stop.

That being said, I wouldn't doubt that the ramp/stop will eventually cause issues, but I have time to figure out how I might do it.

 

It was worthwhile, though, to see that your stop was in fact mashed, which prompted me to open my old valve and see that its stop also was mashed.

Up to that point, the only mashed one I knew of was ozmatt's, from a hot uphill drive on a 40 ℃ Australian day, and the only used EGR valve I had ever bought had its stop in fine condition, so I assumed the mashing was a rare condition.

It appears to be not as rare as I had thought, and is now definitely something I would check on any used EGR valve before installing it.

I was not getting P0401 with mine either at the point where I changed it; my flow monitor was down to about 10 point something kPa (clean and fully functioning being somewhere 20 to 22 ish). It was still well above the 0.97 kPa or so where P0401 is triggered. But now I wonder how much of the reduction from 20+ to 10ish was due to clogging of passages, and how much to the misindexing of the valve.

What flow monitor results are you seeing now?

 

When I checked Amayama, for me on west coast Canada, it’s over $250 CDN all-in.

I wonder if there’s any way to get Toyota’s attention on this.

“failure of pollution control device” might be good subject line.

 

As long as no one yet, to my knowledge, has compared in detail the revised EGR valve to the old one, I find myself wondering if a look at the internal stop design would tell us anything.

 

I lastly disassembled a EGR valve lying around since 2015 or 2016.

This one sat in a Prius from 2010 with about 200 000 km on it.

I don't remember any more what was the symptoms - it was my partners car, she claims, the car "stalled" on her after she pressed the gas pedal somewhat more decidedly (the ICE switched off and she could go with battery, but to start the ICE again, she had to switch the car off, then on again - she explains) - seems weird, so maybe I simple state: the EGR valve was replaced with a used one, but the new design (20 at the end of the part number), in a Toyota garage. I think, they did some reprogramming too. We do not own the car any more.

So - it took so long to find this thread, think about the old valve lying around and disassemble it
Honestly, I hoped, it would be only dirty and sticky and after I clean it, I can sell it as a good one...

Nope!

It has the ramp totally smashed... The metal dip goes all the way through the plastic, and stops softly about 1/3 turn behind the desired dead stop.
Interestingly, if I thread it without the big spring, it stops with a nice click at the desired position, but with the spring in place, it goes without any resistance this 1/3 turn farther and stops softly there.
The spring pushes the rotor upwards, so the dip goes simply over the smashed ramp and stops simply at the bottom plate. Without the spring, the rotor sits lower on the thread and the dip reaches the remaining material of the ramp and stops hard.

I measured the height of the intact part of the ramp - it seems to be 2,3 mm - could someone confirm this?

The thickness of the material at the bottom of the rotor is apparently 10 mm - enough to think about drilling a small hole and placing a stopping pin, as a repairing measure - what do you think?

This kind of failure seems not to be a single or rare case...

Here some photos:

 

^ Just great...

Is there any way to get Toyota's ear on this??

 

... still hoping to see somebody photograph the corresponding stop design in the revised valve they already released years ago for T-SB-0027-16 ...

 

My brother's Prius has this issue, and we figured out a temporary fix. We used an instant set epoxy from Harbor Freight to build a stop in place. And have have P0401 code since the install after let it cure for 24 hours...
We bought an updated version just in case this fix has failed us, but no need for now..

Posted via the PriusChat mobile app.

 

Wow! You could look inside the new one and make few pictures of te ramp!

It would be very interesting, if Toyota changed something inside!

Mat

 

I'm sorry, does that mean you still have the P0401 code? Or that the code has gone away since your repair?

 

Code has gone away, and haven't returned...
It's been a couple of weeks and few hundred miles, have a replacement part on hand Incase it did come back...

Posted via the PriusChat mobile app.

 

Bump?

No pressure, but it would be extremely ineresting

Mat

 

Not everyone is itching to take the cover off a brand-new $$$ part.

I'd do it, though. The disassembly and reassembly are pretty straightforward.

 

It would help if the cover screws were hex-head or socket-head-cap-screw. I purchased a few for next time, hopefully the right threads.

 

The first time I opened one up, spooked by all the reports here about trouble with the screws, I didn't mess around, and went straight to the air-driven Lisle seized-fastener tool.

So I had them out with absolutely no trouble at all, but it also seemed so easy I wondered whether I even needed to use that.

Last time, I just took out my old trusty hand impact driver. Three friendly bops with a hammer on each screw was all it took.

I had mentioned before that the screws just needed a little surprise and then spun out easily the rest of the way. Same this time. After each screw came loose on the third friendly bop, it spun out the rest of the way between finger and thumb.

It's definitely possible to overcomplicate this.

 

I absolutely agree, but, if you don't ask, you will get no answer for sure

Mat

 

Yes, that's probably overkill. I had "absolutely no trouble at all" using my cheap Harbor Fright right-angle ratcheting screwdriver (their Item 92630), and I'm not strong. I can believe it being very difficult if one uses a plain straight screwdriver with worn tip, and doesn't lean into it and maintain good alignment.

 

I tried a JIS (Japan Industrial Stamdard) that’s “supposedly” impact, ie: if you tap the head it does a slight rotate. It didn’t appear to do anything, maybe defective.

Will try my Canadian Tire impact screw driver next time. It worked a charm with Honda rotor retaining screws.