EGR delete or disabling through software

My understanding is there are no techstream adjustments for the egr other than testing it. Others may know otherwise. I don't think an egr reroute is necessary from an exhaust gas flow standpoint as it is routinely off/closed anyway in normal operation like idle and low load situations. It is possible that yours was stuck open to a degree impacting fuel trims.

 

Maybe yes; maybe no?

 

Regarding the second point, how long the engine will last, you should probably know it is widely believed on PriusChat that to do as you have done will lead to a head gasket replacement in short order. I'm not fully persuaded on all the points of that argument myself, but you'll probably want to at least get familiar with the posts of some of the strong believers of that idea.

When the ECM knows the EGR is malfunctioning, it will run the engine with protective fallback parameters trying to avoid damage. If you simply unplugged the valve, the ECM could log P0403 immediately and would run the engine protectively, but with your chosen mod, removing the rotor, you'll prevent the ECM detecting the P0403 condition, and it won't take any steps to protect the engine until it detects P0401, which could take a while.

Regarding using less fuel, one of the purposes of EGR in a spark-ignited gasoline engine (the kind the Prius uses) is to improve fuel economy (that stands in contrast to diesels, where it only helps emissions but hurts fuel economy). So if you are seeing fuel economy improvement with your mod, there is more to the story than your post contains.

 

The EGR system is already designed to reroute the exhaust gases.

This is what helps save fuel.
Friction and fuel burning is what heats up the engine block.

The coolant and oil are what keep the engine cool.

The purpose of the EGR is to recirculate the exhaust and maintain the engine temp.

Saving fuel since the engine does not have to inject more fuel to do so.

Removing the EGR would only waste more fuel and not save fuel.

I would clean the EGR out and put it back.

http://www.RedBullet.net

http://www.ProjectLithium.com

http://www.Pulstar.com

http://www.PlugOutPower.com

 

Some info:

Bad Flywheel | PriusChat

 

I would pay to see this work!!!

 

Mixing raw exhaust with a filtered clean air/fuel mix in is not good for any engine. The sole purpose of the EGR system is to help reduce smog...period. Any warm up benefit is marginal at best.

 

The EGR isn't there for any warmup benefit. Whoever brings that in is mixing up the EGR with the exhaust heat recirculation system (EHRS). They're totally separate systems.



The EGR is there both to reduce NOx emissions and to improve fuel economy, just as in other spark-ignited gasoline-engine cars. The fuel economy benefit isn't peanuts, either.

 

That puts you in direct contradiction of the folks on PriusChat who believe that clogging of the EGR is what causes the headgasket to fail. That's not necessarily a bad thing; we might learn a lot from how you and they work through that contradiction. I'll be watching with interest.

I'm not sure who said that. On diesels it does (or at least used to) lower MPG. On SI gasoline engines it raises MPG (while also reducing NOx emission). The benefit to MPG can be on the order of 18% per this source (for "high-pressure cooled EGR", which is what we've got; "low-pressure" would be taking the exhaust downstream of a turbo), or "between 5 and 30 per cent" per this source, "with the largest improvement occurring in the typical enrichment region." So again, not exactly peanuts.

 

And the Beat Goes On. Back to the head gasket root cause. Early music video (pre Cher plastic surgery) ... advanced control was "electrically they keep a baseball score" while "the cars keep a going faster all the time."

I like the preignition theory combined with excessive oil consumption, thermal cycling, poor head to block ports and the inclusion of a poor egr design.

The primary function of an egr is to add exhaust gases to combustion to reduce combustion temperatures which reduces the formation of pollutants.

However the egr is off at idle and wide open throttle. It does function at part load and effectively reduces the engine size (less fuel air) to allow efficiency and cleaner operation, which is what Toyota was going for on gen3 and reliably achieved on gen4.

 

@ChapmanF

I would argue that you are wrong in that the EGR has nothing to do or will do nothing for warm up time, saving fuel.

That is the sole purpose of the EGR.
Without it the EHRS will not work.

Keeping the engine at an optimal temp.
As it cools down while driving, idling and using the HV battery.

http://www.RedBullet.net

http://www.ProjectLithium.com

http://www.Pulstar.com

http://www.PlugOutPower.com

 

thats insanity! a pc user here claims.

 

First, if you're going to argue with something I said, get what I said right.

Did I say it's not there for warm up time? Yes I did. You're right about that part. I said EHRS is a separate system (and it is).

Did I say it's not there for saving fuel? No I didn't. I've clearly said it is there for saving fuel, even providing sourced references for the fuel it saves. Did somebody else say it wasn't for saving fuel? Fine, 'argue' that part with them.

The EGR doesn't have a 'sole' purpose, it has a 'dual' purpose. In a spark-ignited gasoline engine, it (1) reduces NOx emissions (by a huge amount), and (2) saves fuel.

The EHRS pipes engine coolant through a heat exchanger built into the exhaust pipe, controlled by a wax thermostat opening and closing a valve, as shown in the diagram above and the one below.

If you're prepared to 'argue' how the EGR is somehow necessary for that to work, here's your chance.

 

That very much sounds like the EGR passages in the intake manifold need cleaning. They are proven to clog unevenly, which leads to misfires during active EGR operation. It's not a difficult task but it's easy to miss the small inlets to go to each cylinder port. (Of course, with the valve defeated that's no longer necessary.)

 

@ChapmanF

You said the EGR has nothing to do with warm up time.



http://www.RedBullet.net

http://www.ProjectLithium.com

http://www.Pulstar.com

http://www.PlugOutPower.com

 

Sounds to me like you're about due for a blown headgasket and scapegoating the EGR system as the source of the problem won't mean very much anymore once you're debating on replacing whole engine with low mileage one or just doing the head gasket.

 

Let's compare that to what I actually said.

As you can see, I said it isn't there for any warmup benefit; there's a whole other system that's there for that purpose.

I did not take any position on whether the EGR ends up affecting warm-up time in any way. I don't know the answer to that, any more than you do. It may or may not have some incidental measurable effect; that's just simply not why it's there.

That brings us to you saying this:

Which is just simply false. The EGR is there for two purposes, widely covered in open literature, neither one of the two is what you're saying its 'sole' purpose is, and the idea that the separate EHRS system somehow depends on it is plain bonkers.