Thanks for your input.
Excuse my ignorance, what's the down side of leaving the EGR as intended by the manufacturer?
Hello,
No down side, actually.
EGR, or Exhaust Gases Recirculation, is a device that mixes some of the exhaust gases with the intake air, hence the name. Hot exhaust gas can balance the temperature of the intake air/fuel mix to prevent the formation of nitrogen oxides, which are both a pesky pollutant and a health hazard (as in lung disease/lung cancer) when released to the atmosphere.
Crankcase oil vapors are also routed to mix with the intake air, again to reduce emissions.
Over time, part of the soot from the exhaust gases and the oil from the crankcase can mix into a sludge and build up inside the engine.
Proper EGR functioning requires running the engine at high speed/high rpms periodically, once a month at the very least. The extra load on the engine ensures all the compounds in the intake system, both from the crankcase and the recirculated gases, are sucked into the cylinders and burned, thus eliminating deposit formation and buildup.
This is also the reason why some implementations of this system, like those in the 2L-TE and 1KZ engines, cause so many problems. It is not possible to run these engines at the conditions the EGR system requires to burn everything without risking catastrophic damage. The same thing goes for the DPF in some Toyota models, but that is another story. Even Toyota make mistakes when it comes to engine design.
Yes, EGR/intake deposits can cause problems. One option to prevent this is a catch can, to get rid of the crankcase oil and some of the exhaust soot.
There is an easier option as well: going for a highway run of, say, 80 or so kilometers at high speed once a month or more. Vapors, soot and almost everything else will burn with the air/fuel mixture in the cylinders. Needless to say, it is important to let the engine (and turbo) running to cool down after that.
I would leave the EGR (and any emissions control equipment) alone and I would install a secondary fuel filter. And I would enjoy the chance to go to the highway under the "engine needs a workout to keep the EGR working properly" excuse.
Juan