EGR Clean Fuel Additive.

The catalyst may be cleaner, but how will the EGR be cleaned? Carbon deposits and residues from burning gasoline and oil are sucked from the exhaust manifold and accumulate on the walls of the tubes in the cooler until the cooler is flushed.

 

Snake oil...just like the pour in the tank Cat Cleaners.

 

You have to do physical cleaning one or two of the tubes you can push gun cleaning type brushes through and all of that The cooler may be so clogged it'll take a week to tank and get it cleaned I have two here that still run brown after being soaked for 2 months That's 60 effing days I've blown through them with air nothing too crazy etc and so on when I put the two units that look clean from the external back into the solution brown stuff starts to run out immediately put the chemical in one end and brown comes out the other usually when I clean these things I put the chemical in it runs through comes out the other end no color change when it's clean I have two of these things that have been tanked for 60 days and they're still solid the metals not eaten up or any of that but they are not clean they have a big clot in the middle or down on the end where the gas exits that I cannot get out so there's always that the difference between the cleaned one that doesn't run crap out the bottom end of it when I pour through is quite a bit different and flow than the one that still running brown You can tell it by blowing on the one end with your mouth seriously so needless to say those two that had been tanked for 60 days and still running brown they're not going to be used ever of course I don't have any generation threes to worry about using anymore but still so they can get to the point of no return for sure.

 

Or just clean them? Don’t neglect the intake manifold, it has the final leg of the EGR passages.

 

The EGR cooler would be getting the same effect as the cat from any "cat clean" chemicals present in the exhaust gasses, no? I'm not saying it would work, but if it did work in theory for the cat why not the cooler?

 

EGR is a bit of a backwater, gets some exhaust, intermittently, whereas the catalytic converter is a main thoroughfare, that everything HAS to go through.

I doubt that product has much if any efficacy for either system, but appreciating the effort to manually clean the cooler, pulled out of the car, it's very optimistic to think this stuff added to gas tank will do anything.

 

94k miles isn't a lot. If you have been using top tier gas I doubt it needs to be cleaned at all, but you never know until you look.

 

I would clean it every 50k miles, pretty much the only way to keep it operating per spec's, avoid blowing a head gasket.

Appreciate it's onerous, but until someone drags Toyota into court, what else can you do.

 

In between looks you can ask the car.

 

^ You still need to decide what constitutes insufficient flow.

Exhaust gas may still be flowing reasonably well, but have sufficient carbon build-up on the cooler's internal radiator that it impacts the cooling function. Carbon build-up in that component in particular I would think causes flow to reduce at an accelerating rate.

The intake intake manifold's small diameter EGR passages tend to clog at different rates, with cylinder one being first to achieve near-total clog, while the remainder are still doing ok. Car does not detect this inequity. That's what the head gasket eventually detects though.

 

I don't know that there's optimal conditions to avoid the EGR system clogging. You've heard of death and taxes; you can add 3rd gen EGR clogging to that list. Your situation is admittedly not conducive to DIY. What you can do is research what needed to clean it, and put out feelers to independent garages that could take it on.

I'm a duffer, don't typically do anything more involved than oil and transmission fluid changes, an occasional brake fluid change (if it's not too involved), and general brake stuff. I managed to clean the EGR a couple of times now, takes me the better part of a weekend, it bits and pieces. What I'm trying to convey is that it shouldn't be that hard, for a professional mechanic to take this on.

Take a look at the top two links in my signature, print out some bits, the tool list, the Repair Manual excerpts, approach a few mechanics, see what they say, get some quotes. It should not be over $1000 USD, for a thorough/complete job.

Here's another link (signature won't allow any more), a rough workflow for EGR cleaning, excluding the intake manifold, which should also be done:

Professional EGR Cleaning Resources | Page 9 | PriusChat