I'm surprised you say your Prado doesn't have blow by. I've had catch cans in 2 diesel vehicles that, at various times, collected little blow by vapour, but always showed some evidence they were doing their job. If you have the stainless mesh filter type you may need to kick start the effectiveness of the filter by coating the filter with a thin layer of oil, as they collect oil from the vapour by oil condensing on other oil drops (that's my understanding). If you have the cotton filter type I've found (with a newish engine with little blow by) it can take 5-10,000 km before the filter soaks up enough oil for it to be draining to the bottom of the catch can and be obvious that the catch can is doing its job.Didn’t take pics but I recently took my catch can out. My prado doesn’t have blow by. Catch can was empty after a long period of time.
Got in trouble by my mechanic friend for taking it out. He says he doesn’t care. Good it’s not catching anything but leave it in.
Guess what. I’ve re-installed a catch can to the Prado