[Sankar]

Biggest benefit of blocking EGR is not power, slight power increase is there, is that the intake manifold stays clean and as the car logs on miles the engine performance stays relatively consistent provided other routine maintenance is taken care of. And not all vehicles (even if same make) will have the same amount of carbon in its intake manifold after a set mileage, because the amount of exhaust recirculated depends on the driver also. If he is light footed sedate driver there is more chance of carbon buildup and if he is a pedal monster the build up will be lower.

Cleaning the EGR valve only keeps it from getting stuck, which is good, but doesn't do anything to clear the carbon in the intake manifold and from the intake port in the head and the back of the valve. Cleaning the manifold and the ports can be s hassle depending on the engine. So people abroad generally do either of these two things 1) code it shut and block EGR soon as they buy the vehicle or 2) clean the egr valve, the manifold and port as a DIY coz the shop charges $$$ and then code it shut and block it off saying "can't see myself go through that again!"

The following video is Toyota's 3.0 D4D. Doesn't matter which make engine it is if its Diesel and if it has EGR its the same. VAG and other engines with plastic manifold is crappier and they have other problems like swirl flap shaft getting loose as the plastic its in wears out.

https://www.youtube.com/watch?v=dL1i4qKGcM8

Originally Posted by greenhorn

Heck, my indica has a built in egr defeat that kicks in at extremely low and high rpms'. Dont want to take the nexon discussion offtopic, so cross posting here

Not just Indica, EGR is fully closed when going WOT and at high engine loads on almost all engines.

[fine69]

Bypassing EGR had been on my mind ever since I was told to get EGR cleaned in my 140k run Fortuner. This was around two weeks back but I wasn't sure whether bypassing EGR (or EGR delete as many call it) was a good idea.

Long story short, I researched my bottom off and realized that there are two perceptions to EGR delete.

Yes, these are perceptions because no one really knows for sure what's really happening when you insert an EGR blanking plate (one of the ways to bypass EGR). I went to forums beyond team-bhp in my research and the story is same everywhere.

EGR Delete Theory No. 1

1) Exhaust Gases are bad for the engine, let the clean air in, bla bla bla and manifold along with other mechanical components would thank you
2) ECU is dumb, doesn't know what's happening when you insert a blanking plate so everything should be fine
3) Fresh air means lower combustion temperature and exhaust gases in fact increase the combustion temperature
4) Long engine life, improved fuel efficiency, improved performance - some bhpians have quoted 3-5bhp (perceived) gains etc. Basically its a win-win!

EGR Delete Theory No. 2

1) Exhaust gases aren't bad and in fact do help lower the combustion temperature. Some bhpians mentioned something similar and I read same stuff on other forums as well
2) ECU isn't that dumb and will actually detect a blanking plate (don't know how though). This means an Engine Check Light is likely to pop up or worse, your vehicle goes in limp mode unexpectedly some day (maybe on a deserted stretch in the night, scary stuff)
3) Beyond EGR, there is DPF (Diesel Particulate Filter) somewhere down the exhaust system that would now get clogged because exhaust gases are now getting straight into the exhaust system without going through EGR
4) More importantly though, EGR also acts as the only way of dumping turbo boost instantly in some engines (like 1KD-FTV) and with the EGR blocked, the combustion mixture isn't going to be the right mixture and all hell may break loose

I'm not sure which way I'm leaning right now but I do have some questions, stupid ones at that.

My research was particular to the 2013 Fortuner 3.0 D4D with the 1KD-FTV engine.

Some abbreviations that will be helpful -
VSV - Vacuum Switching Valve
EGR - Exhaust Gas Recirculation (duh!)
E-VRV - Electronic Vacuum Regulating Valve
ECU - Electronic Control Unit (duh again)

The following screenshots of the service manual tells me that EGR system isn't as simple as a valve opening & closing.

First of all, Toyota says that the valve remains shut in only two scenarios (unlike the popular opinion on the internet) -

1) Before the engine is warmed up (I'm assuming temp around 80 degree celsius)
2) Engine speed above 4000rpm

So in the Fortuner, just because I'm accelerating doesn't mean that the EGR valve is shut, unless of course I'm above 4000 rpm which would be crazy, sorry I digress.

Someone please go through the below screenshots and I'll come to my specific stupid questions then.







1) As much as I like fresh air, when we block the exhaust gas re-circulation doesn't it mean that inadequate air is now going to fill the combustion chamber. Given that EGR would remain open once the engine is warmed up, I'm sure its going to pull a certain volume of fresh air and assume that rest of the air is coming the EGR way. Does it mean that the combustion mixture is now not optimum as against the perception that its even better?

2) Inserting the EGR blanking plate means that the exhaust gas is still going to travel the distance to the EGR valve and will find it shut. What happens to the gas that is trapped in the inlet pipe upto the EGR valve?

3) Is it possible that in Fortuner, EGR is indeed used for excess turbo boost dump? If yes, shouldn't Fortuner owners stay away from EGR delete, like far far away!

4) On the very top of the screenshots, it says that one of EGR's function is to lower the combustion temperature. While I understand the whole emission propaganda but would Toyota actually falsify EGR's function in their service manual when all that it does is control emission?

5) Given the not so simple and linear functioning of the EGR system (with VSV, E-VRV & ECU involved), isn't there a high probability of Engine Check Light popping up or the overall engine operation getting hampered just because I was trying be a smart-mule.

Mr. Behram said that EGR is used to control emissions but then the original thread was for a non-ECU based DI engine if I remember correctly.

With ECU based complicated engines, it could make one's life unhappy if it doesn't like the blanking plate. However, many Fortuner owners have done it and haven't reported any problems.

Then there's this other popular lot of BMW owners who's happily deleting EGR but then they are also remapping their cars which means ECU map is changed to delete EGR from doing its regular operations.

As I write all this I think its better to just get EGR cleaned and maybe do it again after another 40-50k kms. Maybe I would've sold this vehicle by then, who knows. But I'm very interested in getting the answers to my stupid questions, it'd make for a great learning if not deleting my EGR.

[clevermax]

A week ago I just got EGR soft-delete and a remap done by Wolf Moto, on my NextGen Verna 1.6D. I am getting at least 1.5 to 2 kmpl increase in my FE with the exact same driving conditions.

In daily commute, I used to get 12.5 kmpl, but after the EGR delete and remap, I get 14.x kmpl. Though I was told that there would be slight increase in FE after the procedure, this improvement is beyond my expectations.

Originally Posted by fine69

1) Before the engine is warmed up (I'm assuming temp around 80 degree celsius)

This is the reason why some people do the resistor trick to manipulate the temperature reading to have the EGR valve always closed.

Originally Posted by fine69

1) As much as I like fresh air, when we block the exhaust gas re-circulation doesn't it mean that inadequate air is now going to fill the combustion chamber. Given that EGR would remain open once the engine is warmed up, I'm sure its going to pull a certain volume of fresh air and assume that rest of the air is coming the EGR way. Does it mean that the combustion mixture is now not optimum as against the perception that its even better?

With an EGR delete, you should get a remap done, is what I could comprehend from my own research. The remap would change the requests, which would take care of the boost and have increased amount of fuel accordingly. Start of injection may also be advanced.