so found out i did have a block off plate on over the hole on the back of the head. apparently the person i bought it from hasn't been running the EGR system. If i decide to just leave it blocked off will i run into any problems with emissions or anything?
Lol am I missing a part that bolts on the head?
- Thread starter Ratrodtaylor
- Start date
Poodles;1918257 said:
What I dont get is, how removing it affects the ECU? Its an unmonitored EGR system, the ECU will just correct itself for the change in temperature would it not? (not looking for a flame war, and it has been discussed elsewhere.. but I have not found anything that indicates how removing the EGR adversely affects the ECU tune). The Exhaust gas temp will rise (apparently by about 100 degree under cruise conditions as the EGR does not function under WOT anyway) but will not harm anything that I can see. (the 91/92 version of the MK3 may have had a sensor.. but I know the pre 89 MK3's did not and the sensor would just verify the EGR was working if I'm correct.. it wouldn't tell "how well" it was working/failing.)
As far as I know the only car that monitors the ECU in the US is the California cars (which I believe is the only way Toyota could sell them in that state). I run without because the part I needed is obsolete (unavailable as OEM) and because I was running with a leaking EGR for about 3 years without knowing it (very hard to see back there) and it was causing issues with a hose back there.
There is a good post with photos on a different forum if you can see it:
http://www.supraforums.com/forum/showthread.php?389759-EGR-Deletion-may-not-be-a-good-idea
Is it better to run with EGR? yes... umm... depending... lol. Can you run without? Depends on where you live. I can legally where I live. No idea of Utah's emission requirements.
Im dangerous.. I kicked the cats out of my car as well just so people can tell me I'm evil...
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3p laid this out somewhere else. Its not that the ECU tune is affected by EGR it's that they have programmed the ECU to expect EGR operation under certain conditions. If you remove the EGR, the ECU still expects EGR under these particular conditions, but has no idea that there is no EGR flow, so the more aggressive timing that is preprogrammed can cause engine damage. And the temperature we are concerned about is combustion temperature, not engine temperature. The ECU has no way of monitoring combustion temps. Most newer cars have some way of measuring EGR flow via a pressure sensor, manifold pressure, or intake volume, but I don't think the 7m ECU has this functionality. Ca cars did have a temp sensor on the EGR valve itself to detect EGR flow, but I don't know if a lack of EGR flow will allow the engine to compensate with different timing maps, or just trigger a code so that you know you need to fix it.
Okay, that makes a lot of sense. Generally speaking though, the EGR system does not inject the exhaust gases at WOT, so the place where the variance would occur (on the ECU map) would be when running partial throttle as it expects that there would be less fuel/air than what there actually is. Therefore we run potentailly leaner. I doubt they would allow the ECU map to let the engine die on a malfunctioning ECR though, so in my head, I still think the risk is very minimal for running without an EGR. Otherwise, it would have been a monitored system. (The Cali situation I believe was forced, not due to engineering preference so is not really a functional sensor, just more of a "yeah.. you have an EGR still" sensor)
Its a tough issue really, because I understand how a properly functioning EGR system would be preferred, but my EGR was actually damaging my engine (externally) without having any telltale signs. Due to its location its just a problem waiting to happen imo. Mine is blocked off properly and the car runs fine without it so far. I just dont like removing something like this without a very clear understanding of the decision and its consequences. All my reading/research points to it having a small effect on fuel economy and a "potential" for issues, but I have not found anyone saying it will actually hurt the engine by removing it.
And in reality.. my car was running for 3-4 years minimum without it and me not knowing it because the gasket on the cooling plate was leaking out the bottom and the shield hose was split open near the top. Could have been like that since 2004...
Its a tough issue really, because I understand how a properly functioning EGR system would be preferred, but my EGR was actually damaging my engine (externally) without having any telltale signs. Due to its location its just a problem waiting to happen imo. Mine is blocked off properly and the car runs fine without it so far. I just dont like removing something like this without a very clear understanding of the decision and its consequences. All my reading/research points to it having a small effect on fuel economy and a "potential" for issues, but I have not found anyone saying it will actually hurt the engine by removing it.
And in reality.. my car was running for 3-4 years minimum without it and me not knowing it because the gasket on the cooling plate was leaking out the bottom and the shield hose was split open near the top. Could have been like that since 2004...
Your point is true. On paper it could essentially damage your engine but in reality who knows. Perhaps you will come across a unique situation where an extended amount of pinging would happen because of the lack of EGR and now you have permanently damaged your engine. I haven't seen anyone directly link an engine failure to a faulty EGR, but perhaps there have been failures due to EGR and the connection was never made. Personally, considering it is an important emissions device and doesn't have any negative affects on my engine, it stays.
^^Agreed, however, I would have kept mine if it was monitored. Because it is unmonitored.. (and obsolete OEM-wise) I left it off.
Higher combustion chamber temps = quicker BHG?
I know that a lot of people have blamed the EGR for a BHG on #6, and then accordingly removed it. I don't buy into this myself, as it makes no sense to me at all, but I've seen it said again and again.
For me, it's not about emissions, it's about fuel economy. Gas is expensive here (And just took a $0.10/litre jump as of today) and I have better things to spend my money on. A functioning EGR = better closed loop fuel economy = good.
I know that a lot of people have blamed the EGR for a BHG on #6, and then accordingly removed it. I don't buy into this myself, as it makes no sense to me at all, but I've seen it said again and again.
For me, it's not about emissions, it's about fuel economy. Gas is expensive here (And just took a $0.10/litre jump as of today) and I have better things to spend my money on. A functioning EGR = better closed loop fuel economy = good.
Im lucky if I can squeeze off 10 tanks a year in my car.. lol.. so gas consumption doesn't concern me. I can see how people can "logically" think that the EGR would overheat cylinder 6 because thats where the EGR port is. Dont know if thats real or not...
Dan_Gyoba;1918408 said:
It's a myth that EGR causes #6 to blow as there is extra cooling capacity to the back of the head specificly for that function.
Like I said, I don't buy it. A correctly functioning EGR should promote a longer engine life, not a shorter one.