EGR Shaft Removal and Possible Disconection

You are supposed to take off the nut opposite of the tab weld nuts .should be some clacking after things are back together but will smooth out,no limp mode

 

Yeah, I didn't find the pintle to be removable. I think people are just shoving it up and down and trying to get it as clean as possible. Some people speak of lubricating it, though I haven't seen consensus on what to use for that, if anything.

To have the very cleanest intake ports after your next 207,000 miles, you should consider keeping the air and gasoline out of there too. Everything stays very clean that way.

If you had a diesel, where EGR is used only for emissions and costs MPG, you could do an "EGR delete" and enjoy more MPG (if you care nothing about emissions).

In a spark-ignition gasoline engine, where EGR is used for both emissions and better MPG, your proposed delete would have the opposite effect (again assuming you have no interest in the emissions part).

If the ECM knows you've unplugged the valve, it will log a P0401 code and light the check-engine light. You can put some black tape over that. Because the ECM knows the situation, it will fall back to a fail-safe policy of running the engine extra gently with extra-retarded ignition timing, so as to prevent damage.

Your other choice would be to restrict the flow in a way that the ECM does not notice. That would avoid the check-engine light and the fallback engine control and ignition timing. It would also be about the same as keeping the clogged EGR you had before cleaning, and carry roughly the same risk of engine damage, whatever that is.

 

What's already burned doesn't burn again. Whenever your engine demand is for less than full power, you need some way to make it burn less stuff. Without EGR, you restrict the amount of fuel/air going in, using a throttle plate. That makes the engine do work to pump vacuum against a closed throttle (this is the same work that "engine braking" does when you slow down in gear). The term for that is "pumping loss". WIth EGR, you can reduce the intake vacuum and reduce the pumping loss, just by mixing in stuff that won't burn. The reduction in pumping loss improves MPG.

That's the explanation a lay person would find very quickly by doing a web search on the topic.

The reason the MPG gain isn't seen on diesels is they already aren't using a throttle to control the power, so they don't have that pumping loss (and that's why, when you want engine braking in a diesel, you need a special mechanism, the Jacobs brake, to make it happen).

That is very commonly claimed here on PriusChat. I don't fully endorse it, but we can go with it for the purpose of your next question:

No, because again, the key fact about recirculated exhaust gas is it won't burn. Mixing it in with your fuel charge means the burn inside the cylinder will have a lower peak temperature and spread over a longer time. That's the whole point of doing it for emissions in the first place: NOx is formed during the hottest parts of the combustion cycle, and EGR keeps those peak temperatures below where NOx gets formed.

In other words, an assumption that EGR would increase in-cylinder temp would be not just a mistake, but flat backwards. Another way to spot the mistake would be to observe that "preventing any exhaust gas from entering the intake stream" is just what happens when the system is badly clogged. So is that good or bad? It probably isn't both.

 

Cleaning tips:

Bad Flywheel | PriusChat

 

Not remotely related to the question you asked, but right now is the best time to install some form of theft deterrent for your catalytic converter. I read about the issue on these forums long ago, but did not think it would happen to me in TX. Got a nasty surprise this January!