I went trough the egr cleaning back in 2020 on my then 160k km prius, it took me aroud 8 hours of long, dirt and tedious work. Afterwards I poured a can of Techron in the tank every 6 months. After 4 years, last week, I performed the egr active test. At step 10 the idle started to slow down At step 15 the engine started misfiring. According to other prius chat threads the above results are a sign that there is no egr flow restriction and it performs nearly like a new one, it seems that Techron did quite a good job at keeping the egr clean. There are many injection cleaners around, but the most effective are the PEA based ones. They are used to clean up carbon deposits from injection, valves and egr. According to wikipedia, PEA also called polyetheramine, is a cathalyst found in epoxy hardener. I have compared viscosity and colour of Techron and epoxy hardener an they look very much alike. I wonder if anyone has ever tried to pour epoxy cathalyst in the fuel tank
at the moment 265k km, I have updated the original post, in 2020 I had about 160k km, based on the fact I drive 25/30k km per year
Over 100K kms since last cleaning, I'd at least pull of the EGR pipe for a look. Maybe also do the intake manifold EGR passages again (presuming you did them before). If you opt to clean (which I would): it goes quicker the second time. Get the EGR cooler out and in the laundry sink, corked-and-filled with Oxi-Clean solution first thing, while you carry on with the rest. Soak for about an hour, rinse and repeat, till clean. If you haven't noticed, check first two links in my signature. On a phone turn it landscape to see signature.
@Abarnabe , how can a PEA additive that is added to the fuel tank clean the EGR system? Please explain it to me.
What did it do to all those sediments at the bottom of your fuel tank? Did it push them into the filter and clog it? If you can't say then you should check...
The PEA is gassified during combustion, then exausted into the EGR, heat will double the reaction speed every 10 degrees of temperature increase according to Arrhenius Equation. According to Techron and Wynn's, once burned, it will break down carbons build up anywhere it passes trough ingluding EGR and cathalytic converter
Reactions at room temperature inside the fuel tank are negligible, as soon as the fuel pea mixture ignites reactions speeds up twice every 10 degrees temperature increase, transforming carbon into ash down stream the injector, but not upstream.
I've just taken the intake and egr pipe off, I wouldn't eat in it, but the build up isn't that bad, maybe as thick as a paper sheet. The valve stems looks ok, port injection does a pretty good job at keeping them carbon free.
So you have a temp gauge inside your fuel tank monitoring this room temperature? Have you pulled the fuel sending unit and checked out the screen to see what junk is on it?
Those photos of intake, manifold and EGR pipe look similar to cars we do daily that have normal EGR intervals on them and are normal/dirty based on the miles. I don't think the money spent really is doing you good, but (it's your money). You could just completely clean everything every 50k-75k miles and go on a vacation with all you saved but I digress.
