Techstream EGR Valve Blockage Data

I don't have a preference about what tool is used to retrieve the test values. Of course it's useful to include whether it reported the values in kPa or psi (or kPa mislabeled as psi, or other similar goofiness, which you can kind of tell by looking at how the min and max thresholds are reported).

I wish the VVT test seemed more usable: the test value appears to be the number of seconds for the timing to be changed by a certain amount. That would be an easy way to check out the claims of an aftermarket product that gets advertised here and is a VVT solenoid that's physically larger (and a different color) and is claimed to improve the "slow" response of the factory system (but without supplying any information about how "slow" the stock system is or what difference the aftermarket one makes).

Sadly, I don't think I've ever seen anybody post a result other than 0.00 seconds for that test. That either means that there is very little opportunity for any aftermarket solenoid to really improve anything, or that the Prius doesn't really implement that monitor.

 

Well I haven't found my Bluetooth ODBII dongle, and the one I purchased won't arrive until tomorrow night. That means I'll just continue lugging my laptop out to the car to use TS.

I did 4 hours of Ubering this afternoon, and put 72 miles on the car. Mostly city driving with the windows down. When I got home, I loaded TS. I see I got a new data point, which is encouraging. It seems to take weeks to get my EGR monitor to set with my 2001 minivan. 15.09 vs.14.76 (Average 14.925 +- 1.1%) seems like normal variability. I'll see if I get another data point tomorrow night.

Something else I should mention is that I always thought that the Toyota recommended oil change interval was 5K, so I have changed the oil with 0W-20 every time the "Maint Reqrd" light came on since I bought it. Maybe the pictures of my EGR cooler will look like the 51K pictures that other guy posted. We will see.

 

Saw this thread pop up again and figured I'd check my car and share another data point. Had my EGR cleaned mid-April and this is maybe 1000miles after:

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MID:$31 TID:$bd
- EGR Monitor Bank 1
Max: 655.34998kPa Min: 0.93kPa
Test result value: 21.34kPa
PASS
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Thanks!

 

When you say the EGR was cleaned, did you have the EGR cooler cleaned as well?

 

what’s your miles again?

The cooler is the main component. What IS sometimes overlooked is the intake manifold; it’s all pretty much for naught if it’s not cleaned as well, it’s egr passages in particular.

 

Yep had everything swapped over with a clean set. See EGR cleaning at 61k pics | PriusChat

 

I obtained this using the Torque app in the "Test results" section. My EGR cooler was last cleaned ~30k miles ago in mid-2017. I cleaned my intake manifold then and again ~2 years ago.

Result:18.28 kPa

Engine has 101k and burns no oil

moto g power ?
View attachment 212184

 

OK, I am an Uber Driver in Philadelphia, and I am driving a 2013 Prius V two with about 95k miles on it. When I bought the car at 22K miles in 2017, I thought the oil change interval was 5K miles. During the entire time I have owned it, I have changed the oil every time the "Maint Reqd" light came on. The car does not burn oil (yet). I have plans to do a full EGR + Cooler + Intake Cleaning (Which I call "the major surgery") next week (end of June 2021).

In order to further this project that ChapmanF proposed above, I wanted to get 5 readings of the "EGR FLOW INSUFFICIENCY" before performing the "major surgery". As will be shown, the value that is reported for EGR flow does vary depending on the conditions when the test was performed.

The EGR FLOW INSUFFICIENCY is part of the "Emissions Monitors" required by our government. ChapmanF suggested that one can read an EGR flow, then "Clear All Monitors" to set the "EGR FLOW INSUFFICIENCY" to zero. "Clear All Monitors" is the same function one would use in any ODBII app (Phone of PC) to "Clear the codes", and turn off the Czech Engine Light. That way, you can drive some more, and if you check again and see a non-zero value, you know that value is newer than the last data point you recorded.

Over the past few days, I have been carrying my laptop under the seat with me while I Uber. Whenever I took a break, I used a phone app to see if the EGR Monitor was marked as "Complete" (I.E. a new value is available). If the EGR monitor is still Incomplete, there was no reason to pull out my laptop. If it was complete, then I fired up TS and took a screenshot of the new value. I also saved the .TSE files, but I don't know if they add any value to this project.

As of last night, I have acquired 5 values:
- EGR-2013PRIUSV-094.290.miles-PreClean: 14.76 kPa
- EGR-2013PRIUSV-094.362.miles-PreClean: 15.09 kPa
- EGR-2013PRIUSV-094.432.miles-PreClean: 14.90 kPa
- EGR-2013PRIUSV-094.507.miles-PreClean: 15.60 kPa
- EGR-2013PRIUSV-094.569.miles-PreClean: 15.41 kPa

Average: 15.16 kPa; 1 Standard Deviation is .35 (+/- 2%)

Note that the weather during all five data points was the same. Temperatures were between 70 and 85 degrees F, dewpoint was in the range of 60-65 degrees F. The last three data points were on the same night. The last two points were dominated by a highway drive of 20+ miles at 60+ mph. Both involved going over a bridge over a major river, so there was hard acceleration on the upstroke, and coasting on the downstroke of the bridge (at highway speed). I am curious if any of that explains the slightly higher numbers.

Stay tuned for photos of the "Major Surgery" that will start on Monday.

 

I had a thought (Dangerous I know). What if we asked people to get the "EGR FLOW INSUFFICIENCY" value at every oil change? It would provide a logical time interval that people might remember. We would then get trend data for that engine. Maybe the trend will be mostly linear, and maybe it will "Hockey Stick" right before disaster. I plan on doing it on both my Prius V's.

 

Had a long enough break in the rain to squeeze in a cooler and valve replacement (using clean ones acquired from another PC member a while back).

Monitor results before replacement:

The 10.41 kPa showing in the Monitor details: a useful Techstream feature I had overlooked thread when I started it back in December was from this car.

Just before starting the work, I pulled up 10.93 kPa. For good measure, I cleared that, made another test drive, and got 10.33 kPa. This is at about 155k miles.

After replacement, I got a reading of 21.19 kPa and another of 21.66 kPa.

I won't pretend I can tell any difference in how the car runs. It seems to run fine, but that's how it seemed before too.

Man, talk about an exhausting job. There are a few under-cover fasteners I'll be putting back in, um, during some future break in the rain.

I'm happy to report that the evil bottom stud does not have to be removed. Its evil nut has to come off, of course, but once the other three less-evil studs are removed, the cooler can just be shifted off that bottom one. It's even kind of handy as a position reference for jockeying the replacement cooler into place.

Just like my first experience with changing the coolant, it seems that the fill and bleed procedure has been really well dialed in by Toyota with this degas-bottle system. I have a 2010, so I have the bleed screw in the hose junction above the cooler. I have to fill the bottle just barely above the B line to get some dribbling out the bleeder. Then I just followed the manual, which says to close the bleeder and cap the degas bottle and run the engine up to temperature. You can watch the air bubbles being delivered to the bottle through its upper hose, and, after seven minutes or more running at full temp, I shut it down, waited for it to cool down, and just like my first time, the coolant ended up right at the F line, just like the engineers knew what they were doing.

My removed valve and cooler are right here, waiting for a moment when I'm less exhausted and can report more on their condition. The cooler wasn't completely blocked—light can be seen through it—but such descriptions don't translate easily to flow capacity, and I'd like to think up some reasonably repeatable way to measure that, before and after cleaning.

One might assume that because this replacement roughly doubled the car's monitor reading, the old one's about half occluded. But a direct measurement could be a good check on that assumption.

 

Wow ~10.5 to 21+ is quite an improvement. Was this just the EGR + Cooler, was the passages Intake manifold already cleaned? I got 20+ after only doing the EGR and Cooler, but it went down to a repeatable and improved 15.6.

I finished by completing the complete EGR circuit by finishing the intake manifold last night. Just in time for company to come over. When I started for the first time, The engine made a really awful noise that threw a Czech Engine light. It settled down, and the MIL went out. I got a bunch of codes, and I took a screenshot. I'll do a complete report on my own thread:

My Major Surgery saga on my 2013 Prius V. | PriusChat

 

These are my data:
2010 Prius with 167,000 miles.
Oil change (0-20) every 9,000-12,000 miles, without significant consumption.
The engine runs normally but I have the feeling that at 1500-1700 rpm and with the EGR open 30% (according to Torque), the engine has some vibration, with the EGR closed it does not happen.
Should I be worry? It's a bummer because it's not easy to find someone to do the work in my city.

 

@Prodigyplace should be along shortly.

 

Did the manifold a year ago May. Assumed it's probably still ok and didn't go there this time.

 

20.54 kPa looks like a very good overall reading to me, comparable to those reported by other members after cleaning.

Have you checked the condition of the individual passages in the intake manifold? That is a much easier job than the rest of the EGR system, and differences between ports there may not be reflected in the overall flow result.

 

Why? I have nothing against Czechoslovakians. My Dad worked for one for several years in Canada. He called himself a bad Czech.

 

Always trying to “pass himself off”?

 

Since April when I took my first measurement I keep watching it. Not often, let's say once/twice a week. All values were 18.xx kPa.
But three or four days ago it drops to 13.xx kPa. And stay there.
Should I bite the bullet and try to do a full EGR/intake manifold cleaning?

Car has almost 200k miles and I bought it 3 years ago at 170k miles. No weird behavior, it sounds and drive normal, all fluids are steady, 45 mpg driving in the city with AC on, no white smoke, no milky oil on dipstick.