What can influence EGR cooler clogging?

In my adventures to find a replacement vehicle for my daughter, I spoke to Todd over at Tampa Hybrids...who knows his stuff. He had some interesting insight.

He said that that they generally replace the EGR cooler on *all* of their vehicles if they have 160K+ miles on them. Granted, these are 'Florida cars' with relatively high mileage ( it's rare to see a Prius in his listings with under 120K miles ). He has seen and sold thousands of vehicles...so I value his thoughts on it. Like I said though....he is dealing with hot weather 'Florida cars'. A colder climate will definitely change things...

Below is for the OP....( not @Raytheeagle - he knows all of this already ...haha ) :

The EGR clogging debate has been the source of endless discussion around here the last few years. No definitive answer either...as far as I can tell. Search on it and you will find more debate about it that you ever wanted to know about.

 

Toyota mechanics and other well compensated shops replace rather than spending hours cleaning and reinstalling used parts.

 

Yep. My point was the mileage interval where they make the decision to change it...not the fact that they use a new one.

But that is a great observation. And that is exactly what I did when I did the EGR maintenanve on our Prius v (wagon). I got a 'new' (to me) EGR on Ebay, cleaned it, and then swapped it. I then cleaned the old one and now I have a 'spare' to use. I *was* going to use it on our 2010 liftback...but that was recently totaled due to an accident. At any rate, I'll have the EGR cooler on hand for the next Gen 3.

 

Right. But Toyota will also install a new egr valve. Quoted at $800 for cooler and valve installed. 160k miles is probably way too long on an early gen3 but it may take that long to actually throw an egr code. Plus the egr is closed much of the time anyway.

 

Well...when I changed the EGR on the 2012 Prius V (wagon) at around 130K....it actually wasn't all the way clogged. Frankly, I value Tampa Hybrid Todd's opinion over any of us with our very limited dataset....haha. However, I agree...his 160K number seems pretty arbitrary to me. And again...his climate is *far* different than mine is up here in MN.

That's why every situation is different. Personally, I think it has something to do with the climate and the 'highway to city miles ratio'. However, just like everyone else, no conclusive proof.

 

I'm in favor of keeping an eye on the car's measurement of EGR flow (and reporting before/after numbers and visual condition when cleaning).

 

I’d rather be early than late; especially the first time.

 

It's all good; the more "rather be early than late" folks as well as less-proactive folks there are who report their before/after flow numbers and visual results when they do their cleanings, the more evidence we get for "rather be evidence-based" folks to rely on.

 

I agree!

I'm late to the 'measuring EGR flow' party...how do you guys do that? I'm assuming through an OBD2 reader and some app?

 

I assume this information requires Techstream? My installation broke after a windows 10 update. My intended EGR Cooler cleaning was supposed to start today. It got delayed a few days. It will rain tomorrow. I would like to oblige in providing any before / after info to post, if you tell me what to look for.

I think my 2013 V with 94k would be a good data point. I bought the car with 22k off a 4 year lease. Then I started using it as my Uber / Lyft vehicle in Philadelphia. Mostly stop and go city traffic, with random long distance runs thrown in. Also, some idling with the AC on high. Good range of Summer and Winter driving.

I don't think the buildup will be that bad. I am looking at this project as insurance to get the most miles I can out of this car as I can. I bought someone's spare cooler on eBay, and I expect this to be a regular maintenance item.

 

The car itself does an EGR flow test every so often and records the value. Any reader that can do a "mode 6" query for monitor test results can show you what the latest result was. Techstream can do that, of course ("engine control and ECT", "Monitor", "Details", "Exhaust gas recirculation"), but so can lots of people's phone apps, etc., as you can see in the thread that I linked to above.

Techstream displays the value in kilopascals. Some other apps display it in psi. At least one example was posted in the other thread where the number shown was kilopascals but labeled psi (oops!). There might be some readers out there that can bring back the result but don't know the units and scaling, and just show a raw value; if that happens, it can be converted using the formula shown in the repair manual.

Any time you do a code clear (even if there weren't any trouble codes to clear), the monitor results get blanked out, so the next time you retrieve a result, you'll know it's a fresh one.

 

Using a phone app would be simpler than getting Techstream working again. I have Torque Pro on my phone, and I loaded a Toyota profile. Way too much information to sort through.

I like the idea of grabbing a result, writing it down, then clearing the result. I can get some before numbers pretty easily.

Any idea when the EGR Monitor test runs? According to some apocryphal sources on the Minivan forums, My minivan requires 20 minutes of 40+mph driving followed by coasting to a stop, without touching the brake. All I know is it only seems to happen when my wife drives it.

 

It gets snuck in during decelerations when the engine is running and the fuel injection is cut. There's a "confirmation driving pattern" in the repair manual section for P0401 if you want to hurry it along, roughly involves taking a drive in inspection mode with warming up, 5 minutes around 25 to 37 mph, half a minute of idling, back to 25 to 37 mph but in B gear, and a foot-off-the-pedal decel for at least 5 seconds.

 

Just to note: in the intake manifold, if Exhaust Gas Recirculation capillary passage to cylinder #1 (for example) is completely bunged, but the other three have some flow, everything’s ok as far as the computers are concerned?

 

Well put, and a good reminder why a check of the manifold (which is a cakewalk compared to a whole stem-to-stern valve-and-cooler project) could very well be a wise thing to combine with regular monitoring of the flow. The conditions of everything upstream of those manifold passages will be reflected in the flow test.

I checked my manifold last year, and knocked out the roughly paper-thick accumulations of carbon I found in those passages at that time.

 

Interesting... I think I learned about "Inspection Mode" from a video about changing the radiator fluid. I just need to know if I can get the info you want from Torque, or should I spend today getting TS to work again.

You mention "repair manual" in several of your posts. Which manual are your referring to, and can I get one?

 

Manual on engine coolant replacement.

 

I am willing to hold off my EGR cooler cleaning on my 2013 Prius V for a few days (Actually it is raining today).

Can someone please tell me what specific steps I would need to take to gather the information that would be most useful?

Torque Pro:
I have Torque Pro installed on my phone. I am not an advanced user of the app, but I can follow instructions. Mostly I use Torque to monitor the emissions monitors on my 2001 minivan, and clear them when the Evap test fails.

Four years ago, I imported a "Toyota Prius" profile that gives me a long list of (continuous ?) parameters I can add to a display to a "Realtime Information" widget. The only EGR related parameter is: "[PRIUS]EGR Step Position". I don't know what generation the parameter list is for, and I strongly suspect that "EGR Step Position" is not helpful. If there is a place I can get a better profile to import? Alternately, can someone provide instructions on how to build the Mode $6 command to get the EGR flow rate? I have a rough idea what Mode $6 is, I just haven't tried to use it on Torque. I used to write code for Cable TV boxes, so you can assume I know what Hexadecimal numbers are..etc..

Techstream:
I believe that TS would be the most desirable way to go. I had a working installation (16) that broke when Windows 10 updated a few months ago *. I was told to downgrade to a (15) version that does not need a key rather than get a new key. That version doesn't recognize my Prius (perhaps I installed it incorrectly). I don't know how much work it would take to get the software to work again, but at least the Dongle driver is working.

I want to get TS to work again, if for no other reason that I have 2 extra wheels that I use spare tires with known TPMS IDs. When I get a flat at 9:30 on a Friday Night, I can go home and put a real wheel on the car. That way, I don't lose my most profitable hours of the week for Ubering. I can get back on the road with minimal delay. The tire can get fixed on Monday, but Ubering with a donut is not a good idea. I want the ability to turn off the TPMS light, so my passengers have one less excuse to rate me less than 5.

What I need:
Getting the data via Torque pro would be the simplest for me to get the "before" data, If I am given instructions to get useful data. It also requires my finding my Bluetooth Dongle, which is not plugged into my Van or the 2013 Prius. Fixing TS is something I want to do, but will require more effort. It would be best if I can the requested data by the end of day Wednesday, so I can Uber this weekend.

* I have heard that Windows 10 deletes registry entries and / or files of non Microsoft approved software during upgrades. I might be able to get my TS vers 16 to work using the original key.

 

If a post is from me and says "repair manual", it only ever means the Repair Manual, and there's a whole wiki page that Elektroingenieur kindly put together with pretty much all the ways of getting access to Toyota's technical information from various parts of the world, including ways with fees and ways without fees that might be available through local libraries, etc.

 

OK... I will check it out again. I don't recall the options options ALLDATAdiy.com and Mitchell1DIY. when I looked back a few years ago.

A few years back I considered the option of renting a TIS subscription for a weekend, and spending 18 hours in a download orgy. I suspected the result might be like the post above by Ms Rudkis of the procedure to do a cooling replacement. Buried in that .pdf is a broken link to how to put the car into inspection mode. The Youtube video on the same subject is more complete, although maybe not as trustworthy.

Having a collection of .pdf files with broken links is better than nothing. It forces you to search all of the .pdf files downloaded, every time there is a link to another document. If the broken link points to a file you did not download... er well... Also, you don't get updates, but if your car is four years old, any important updates would be raised in this chatroom.

The DIY links may actually be what I need.