E g r deleat

What is the advantage of deleted egr.

 

Well if you have removed the plenum from the 3VZ-E engines intake manifold and have removed the throttle body you can see the obstruction that is the EGR mixing pipe that enters the plenum from the other side that is opposite from were the throttle body is located. This flanged pipe is inserted into the plenum and runs about half way back toward the throttle body which promotes mixing of the recirculated exhaust gasses with the air that is coming past the throttle plate and into the plenum. By removing this pipe the central port in the plenum is opened up in cross sectional area by the amount that this pipe had occupied when it was installed. Aside from this physical improvement in potential air flow that removing this pipe can afford the other change is the fact that hot exhaust gasses are no longer put into the engine and mixed with the ambient air that is drawn in. This may increase the time it takes for the engine to reach operating temperature and therefore allow the ECM to run in closed loop or not depending on how the logic in the ECM works with turning on the EGR system as it does have a temperature probe that is mounted in the EGR's control valve casting.

I can attest that upon my tare down and rebuild at 232K the amount of carbon in the plenum and on this pipe was extensive. I suspect that the PCV and the valve cover vent pipe that is in front of the throttle body would both allow combustion gasses to coalesce there particulates at the EGR pipes opening with the heat generated from the exhaust gasses there in. Certainly the emissions that the EGR system addresses will be higher with it removed. But the pair of diaphragms, vacuum lines and the port coming from the exhaust can be removed and capped off respectively with a kit that LC-Engineering can supply. For certain the EGR system is a very much an OBD 1 manifestation for emissions and there is something to be said for increasing the intake air temperature for volumetric efficiency's sake. But I suspect the enhanced flow with the pipe removed is a better gain than the air temperature in the manifold being elevated by the EGR as heat soak from the intake and plenum will accomplish most of this as the engine is warmed up. Not to mention the fact that the entire intake porting of the plenum and intake to the valves will stay a good deal cleaner as mileage is increased over the engines useful life.