Hi…so the EGR cooler was heavily clogged. I could not see light out other end. I went through 3 cans of brake parts cleaner when I realized this wasn’t doing anything. I noticed the cleaner was a light color with the only a small amount of black flakes. At this point, I was thinking I am going to have to buy a new one. I thought I’d try using air compressor to spit out the junk. It worked but I would say I spent 90 mins patiently blowing out the debris. I would spray brake parts cleaner after a bit and the cleaner coming out was now black with bigger black flakes. I repeated process until the cooler stopped looking like a muffler spewing out dirty air and cleaner was light colored. The hardest areas were the top, bottom, and side rows. Am happy with the results and am able to see light out the other end,
That sounds like a lot of work. If you have a chance, you might post your EGR flow numbers after it's all back together. It's most useful to post both the before-cleaning and after numbers to compare, but of course that only works if you did get the numbers before cleaning.
Try soaks with a hot tap water concentrated solution of Oxi-Clean Versatile Stain Remover (somewhat caustic, powdered laundry additive). Cork on end, pour in, prop in corner of laundry sink (or what have you) and give it an hour. You should see it foaming out the top, with flecks of carbon. If it's totally bunged up with carbon you'll likely need to help with a wire gently pushed through the passages of the internal radiator. Something like a regular diameter coax cable wire (copper), with the end deburred, is good. After about an hour it'll subside. Pour it out, rinse and repeat. Five or so soaks thus should have it like new. For procuring corks of the right size: Intake opening diameter (at exhaust): 20.9 mm exit opening diameter (at EGR valve): 25.7 mm How many miles on it btw?
Wow! Great tips…I will try the copper wire to make sure before putting back. I will know to use the oxi-clean next time. Thanks …ps have 145k miles bought with 132k back in 2020
the work wasn’t bad I have plenty of time to spare. I didn’t know about EGR flow numbers but am sure it will be working a whole lot better than before. If I can figure out how to get numbers, I will post.
If you did not disconnect the 12V battery or clear codes with a scan tool, then the "old" numbers are still in the ECM. Techstream is fairly easy to display the monitor results. I think you connect to the ECM, click on monitors, then on the question mark to the right of the EGR monitor. Most other scan tools have the same data in the "generic or global" OBD2 section under mode06 results. If data was cleared, then drive the car for a couple weeks and check the results when the EGR monitor is "ready" or "ok" or "complete". I have found on stubborn carbon deposits, you can use easy-off oven cleaner if the parts are (stainless) steel or iron (NO aluminum or fancy valves or electronics). Posted via the PriusChat mobile app.
If that 18.20 kPa is the remembered number from before cleaning, the cleaning probably could have been put off longer. Freshly, thoroughly cleaned seems to come out around 20 to 22. If that's a number from after cleaning, then it looks like a Pretty Good cleaning job.
