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nissan patrol Gu6
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Discussion Starter #1
Just blocked the EGR valve on the crd and what a difference in performance. Turbo spools up significantly quicker and the scangauge shows a slight improvement in fuel usage. I blocked it at the valve end of the egr.

The boost on the scangauge shows it has risen from previous peaks of around 15psi to about 16.5psi. I don't have a EGT gauge as yet. Its currently on its way from McNally in U.S.

The other improvement which I have always had a problem with is black smoke (excessive), I can't see any smoke which I would always see on acceleration, especially 1st to 2nd gear. Not sure why this would improve?? Sure am happy:p
 

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Did it on mine recently as well and it makes a noticable difference. Has yours thrown any EGR fault codes yet?
 

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nissan
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Mine throws the code every 2 weeks on average, I've been told you need a 8mm hole in the blanking plate to prevent it, this seems to defeat the purpose IMO, so I'll just keep clearing them with the scanguage.
 

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Mine keeps thowing fault codes. I just delete them.
Is there a problem driving around with the codes?
Does it send it into limp mode if it gets enough codes built up?
Will fault codes effect the normal vehicle operation?
I don't want to drill the 8 -10mm hole in the plate either. But if I have to I will.
What are the options?
 

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does a catchcan stop the code from coming up?
 

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No, catch can has nothing to do with the fault codes.

I does keep your intercooler and piping clean though.

EGR codes don't seem to cause any issues with how the car drives. Hoping someone can shed some more light on the fault code issue. I never get the engine warning light up though so it can't be too important.
 

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...EGR codes don't seem to cause any issues with how the car drives. Hoping someone can shed some more light on the fault code issue. I never get the engine warning light up though so it can't be too important.
Thats odd...

P0401 ( the EGR fault code) should illuminate the "Check Engine" warning lamp.

What code/s are you getting?
 

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When blocking the EGR on a CRD, is it necessary/preferable to install a Dawes & Needle valve? Or does the ECU manage boost?
 

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With the codes, does the scangauge completely clear the error from the memory of the ECU? Or does the ECU 'remember' that these codes occured even if cleared? I'm thinking warranty implications here.
 

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Hey Guy's,

Will follow this thread with great interest as looking to do myself but worried about having engine drama's.

I've herd you need to change the turbo's psi with an adjustment screw to bring it back in line??? Will that stop the codes from coming up???

Cheers =-)
 

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I agree with TET the P0401 error that comes up from blocking the EGR does illuminate the engine check light. The scanguage clears them out completely (asked the mechs when the CRD was in for the stuffed fueling system what codes were showing with their computer). It does not go to limp mode with P0401.

The EGR valve on the CRD is electronically controlled and has a sensor that detects the EGR gas when it is open. The P0401 error with mine hardly ever comes up in the north but when I drive down south I see it more in the cooler temperatures possibly indicating it works by temperature.

The dawes valve appears not needed with the CRD as the ECU controls the boost well. Even with the EGR blocked and a 3" system I hardly see the boost spike any higher than 20psi and only for a short time. In leiu of what Justautos is doing to his CRD in regard to boost I feel this is really at the low end of the worry spectrum.
 

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Hiya Brad...

Yeah, mine is almost exactly same behaviour as yours.

I have only seen P0401 about 4 times and I'm not intending to drill the plate (defeats the purpose IMHO) when the Scangauge clears the code and the Memory.
 

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Hi TET

I cannot understand why anyone would go to the trouble of blocking off the EGR and have a hole in the plate. Defeats the purpose of doing it.

I might see the error a couple of times in one day but then not again for 6 months. The scanguage clears them out completely.
 

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Hi TET

I cannot understand why anyone would go to the trouble of blocking off the EGR and have a hole in the plate. Defeats the purpose of doing it.

I might see the error a couple of times in one day but then not again for 6 months. The scanguage clears them out completely.
Ok, I will fess up :p

I made that suggestion (10mm hole) quite some time ago for the people that did not have and were not going to have a scan gauge installed to clear the codes.

It should still minimise the amount of EGR in the intake without the code being thrown up - better to fully block it and get the scan gauge but not all want to go down this path.

:cheers:
 

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Yeah, thats cool Whitie, I understand.

Why anyone with a CRD wouldn't spend $200 on a Scangauge defeats me a tad... Mine paid for itself in about 4 or 5 months on fuel savings alone in the Patrol and I use it on about 3 different vehicles at home altho it spends most of its time on the 'Trol
 

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The EGR valve on the CRD is electronically controlled and has a sensor that detects the EGR gas when it is open. The P0401 error with mine hardly ever comes up in the north but when I drive down south I see it more in the cooler temperatures possibly indicating it works by temperature..
can the sensor that generates the p0401 code be disabled?
 

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I have a Launch Creader 5 and it brings up the P0401 egr insufficent gas flow. I have never had the engine light come on. The Creader clears them off without issue. If it does not go into limp mode then who cares if it stores the codes.
A funny thing though is i had heaps of codes come up for the first week of installation of the egr block. Now nothing for the next week, strange.
 

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JohnH
can the sensor that generates the p0401 code be disabled?
I am led to believe that Iif you disable it by cutting the wire, the ECU will fault giving a permanent EGR error. Easier to buy a scanguage 2 or equivalent.
 

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I have a Launch Creader 5 and it brings up the P0401 egr insufficent gas flow. I have never had the engine light come on. The Creader clears them off without issue. If it does not go into limp mode then who cares if it stores the codes.
A funny thing though is i had heaps of codes come up for the first week of installation of the egr block. Now nothing for the next week, strange.
Some info taken from the 2007 ESM for CRD below. Surley there is an Electronics engineer out there who could rig something up to dummy the ECM into thinking it was receiving the correct signals. The EGR remains closed under certain conditions. Could a false signal be sent to the ECM?

DTC P0401 EGR FUNCTION PFP:14710
Description BBS00CK4
SYSTEM DESCRIPTION
*: This signal is sent to the ECM through CAN communication line.
This system controls the flow rate of EGR led from exhaust manifold to intake manifold. The opening of the EGR passage in the EGR volume control valve changes to control the EGR flow rate. A built-in DC motor moves the valve continuously corresponding to the ECM output signal. The EGR volume control valve control position sensor detects the valve position and sends the voltage signals to the ECM. The ECM judges the current opening angle of the valve from this signals and the ECM controls the DC motor to make the valve opening angle properly. The opening of the valve varies for optimum engine control. The optimum value stored in the ECM is determined by considering various engine conditions. The EGR volume control valve remains close under the following conditions.
l Engine stopped
l Engine starting
l Low engine coolant temperature
l Excessively high engine coolant temperature
l High engine speed
l Accelerator pedal fully depressed


The ECM has a learning mode which I think would explain why some guys are seeing faults then nothing for a few weeks. (Another Extract taken from ECM Below)

EGR Volume Control Valve Closed Position Learning BBS00CPK
EGR Volume Control Valve Closed Position Learning is an operation to learn the fully closed position of the
EGR volume control valve by monitoring the EGR volume control valve control position sensor output signal. It
must be performed under any of the following conditions:
l EGR volume control valve is removed.
l EGR volume control valve is replaced.
l ECM is replaced.
 
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