EGR and engine failure?

Yeah I call BS on this: they all clog.

 

+1.

I regularly (as in everyday) drive 65-70 mph for 30 minutes and I have cleaned the circuit twice.

But I know how to do the job through practice .

 

Assuming no need to clean, just parts swap, how long does it take you now? I'm guessing under 3 hours. You leave that lower cooler nut off?

 

Under 3 hours, if only .

My best is 5 hours and that is with 2 sets of experienced hands assisting.

But I have been accused in the past of not being the sharpest knife in the drawer.

But I do leave the cooler nut off.

 

I probably take 3 hours getting the windshield cowl off and everything back together. And that's just an appetizer.

 

I’m including pre and post work like splash shield removal and replacement in the time quote.

That windshield wiper cowling is definitely in your craw .

10 minute disassembly and 15 minute reassembly due to usually putting one but in an incorrect spot leading to rework .

But not too bad overall .

 

In other EGR systems the problem is low temperatures. Also, wouldn't the change to post-cat supply raise the gas temperature? It would certainly cut down on the unburned hydrocarbon content, so less latent fuel in the EGR...

The big difference in my mind is that a pre-cat EGR source allows the engine to actually use some of the recovered HC in the exhaust, the post-cat system sacrifices that but gains hotter, more stable EGR flow temps with less random garbage in it.

 

Lot of info there, thanks.

The 4th gen EGR cooler is a different shape too. It'd be nice to be a fly-on-the-wall in the engineer meetings.

 

congrats!

 

I presume they only replaced valve and that they didn't replace or clean the cooler?

 

i just experience the same thing as this one.

 

Can you provide more information?

 

Hi trying to delete my comment.....
Tools say edit and report... no delete option.

 

Thank you!!! This is the info I was looking for! suspected head gasket failure, check and clean egr tube.

With the obdll and car scanner app, is there a way to tell if the EGR clogged by looking at like the temperature of the fuel the oxygen sensor or is there something that I could check on there that would tell me the EGR is clogged.
I mean, you can answer this but this is what the problem is and know that I just got to do the work. Checking more is not going to help it get better. I need 2 willing helpers that know what they're doing. I can do thinking but I don't have much confidence in doing that job by myself. If it took 5 hours with two people assisting to get the whole job complete. Ugh.

 

You guys think that maybe the cat clean stuff would help the situation at all? Someone said it got rid of his catalytic converter codes would it recirculate back through and hit the EGR system. Dang, I know the answer is probably no... I also saw that someone used sea foam in the intake (?) To clean the manifold. It's been a little while since I watched that video.... awe. My car.

 

I just got the cataclean to maybe buy some time. If it performs miracle, ill definitely come back and let you know.

 

All these theories as to what causes the 3rd Gen EGR system to clog up with carbon, all it takes is Toyota's poor, untested design and 100k miles.

Driving slow, driving fast, oil consumption or no, doesn't matter. Testing if it's clogging is not necessary, just the odomoeter's all you need: clean it at least every 50k miles, if you want to keep it functioning properly, with sufficient, balanced, and cooled exhaust gas supplied to the combustion chambers.

Or wait for the head gasket to blow, and once that happens, a belated EGR cleaning isn't going to fix it.

There's relevant info in my signature; on a phone turn it landscape to see signatures.

 

Yes you check the egr active monitor value. If it too low there is no egr flow.

The value of 20 psi indicates a completely unclogged egr system. This test is automatic on most drive cycles and will code if it fails.



The egr system is designed to block all egr flow at startup and low speed engine operation. Plus at wide open throttle. The car will not run rough with a closed egr valve or with a clogged egr cooler.

The original Op's problem was solved by a new egr valve. This indicates the old valve was sticking open at startup and low speed operation causing engine stumbling. Toyota has a revised valve and software.

An egr system flow blocking test easily determines if the egr valve is sticking at low rpms causing rough running.

Car care Nut Egr video with block tube test

P0420 is an inefficient catalytic converter. Additives don't work.