"EGR DELETE" Instructions

I believe you will get a CEL code with blocking the flow or unplugging the valve. Two different codes, possibly. The system is expecting a certain air pressure in the manifold. That's the MAP sensor's job.
It would be easiest to put a thin metal 'gasket/plate' at the intake to 90° pipe. You can make quick with and without tests!
I doubt 'soot would build up in the cooler if there is no flow going through, right?

I was planning on using small brass wire rotary brushes in a drill to clean the very small EGR passages in the intake.
But alas, I came to a better solution!
Bail on the Gen 3 and buy a Gen 4.

I'm sill learning about that new EGR system but it sounds much better and does not require so much routing cleaning.
I bought a '19 Gen4 Eco in Dec '25 with 232k miles, for a song, and it's now at 252k mi. Yes, it's a work car! And it gets much better mpg than the Gen3. Doesn't seem to use oil and keeps it fairly clean between 5-7k mi changes.

Who needs a '10 Gen3 Level 5 with the Advanced Tech Package, but not the 17" wheels?

 

Or just give it a try for a day or two. If you have an OBD adapter and free app you can clear the code after plugging it back in, and/or check the codes once a week to see if any other code has popped up.
I did mine and the change in smoothness was immediately apparent.
It used to hesitate and feel like it was stumbling a bit on light acceleration.

 

I cleaned my egr system and maniford at about 130k. It wasn't too cruded up but I drive the speed limit and don't floor it. I was interested in egr delete which I did and am very happy about it. No problems and get the same mpg. Looked into the egr data. They say engines run 100 to 400 F hotter without it. I have a scan guage 2 and have never seen the temp go over 198F. Here in NE the big seller is 10% ethanol which they say runs 100F cooler then straight gasoline. The egr system only runs part time anyway so I don't get the worry that the engine will run hotter and cause head gasket problems. I would think the manifold cruding up is problably the most likely to cause head gasket failure. Just my 2c worth. I am now at 167k and car runs great and haven't seen any drop in mpg.

 

Sounds like you are conflating two things (which happens a lot in EGR threads): the temperature reached inside an engine cylinder, for milliseconds, in the cloud of burning mix, and the temperature the massive engine itself (block, head, head gasket, and coolant) reach.

When "they" say something runs "100 to 400 F hotter", they're talking about that peak burn temperature.

Your ScanGauge shows you that macro engine temperature, seen in the coolant. You're not going so see that change much, because there's a thermostat controlling it, and a radiator. And the thermostat and radiator are sized to keep that temperature fairly stable even under the much bigger changes like when the road goes from downhill to up.

An engine/coolant temperature 100 ℉ hotter than normal would be way past overheating ... to say nothing of 400 ℉.

 

An “EGR delete” and “EGR cruding up” amount to the same thing.

 

Maybe.
That would depend on whether the "delete" is by unplugging the connector or by otherwise blocking EGR flow, and whether the "cruding up" is in the cooler, or only the EGR passages of one or two cylinders.

 

Yes, I meant peak combustion temperature without egr is 100 to 400F hotter than with egr. 10% ethanol lowers peak temperature 100F. Driving the speed limit I rarely see rpm anywhere near 3000. Anyone recall when the engine computer calls for egr?

 

Mostly in the mid rpm range, tapers off towards the idle and high rpm ends.

 

Most definitely ,, No.

EGR valve unplugged = No flow through that system.

EGR partially plugged up happens unevenly and the #1 and #2 cylinders get plugged first and that's usually where the head gasket fails.

 

I always drive +5 the speed limit, which can be 80 mph true speed (not indicated speed), and I floor it as needed. I deal with tricky interstate on ramps....

I really felt the car was smoother when adding light throttle while at low to medium speeds. There was immediate response and no slight stuttering.

The only problem with the EGR unplugged is having the permanent CEL light. Ideally you should check your codes once a week or so to see if you have anything new, other that 'EGR' code....

 

Better let Toyota know, the whole EGR enterprise was for naught, lol.