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[Broomies Mate]

Hi Folks.

Astra G (2002 Z16XE)

My brothers Astra is running like a pig. I plugged it into my Diagnostic tester which gave P0400. EGR Valve at fault.

When I ran the EGR Solenoid test, the car stalled. Is that meant to happen? I am guessing at idle, if the EGR opens, the inlet receives hot air, so will stall..... BUT, if my Diag-Hardware can open the EGR, why is there a fault? Is it possible that the EGR isn't closing fully, causing the poor running but the ECU is telling Diag that the EGR is fully closed?

My Diagnostic reports the EGR valve is closed at idle (which it should be) but still closed when under heavy acceleration...... is this right? I take it the ECU hasnt been updated to ignore the EGR else the fault code wouldnt have been flagged?

The other problem with the Diagnostic readout is O2 Sensor 1 Bank 1 is giving very odd fluctuating readings (fine then very low, fine then very low). O2 S1B2 is reading perfectly.

On Saturday I'll remove the EGR and the ICV and give them a good clean, but is there anything else I should be doing?

Sorry for the very fragmented post, I am confusing myself so god knows how you will be able to read it. 

(as per OOF rules, I have removed the name of my Diagnostic technique) 

[Andy B]

Tech II can tell that engine to treat the EGR as though it's not fitted.

[Broomies Mate]

Tech II can tell that engine to treat the EGR as though it's not fitted.

It certainly can, but I'm concerned that the EGR may not be the problem, or just part of the problem due to the O2 readings, or is this likely to be linked to an EGR problem?

There is no record in the SH of the Cat being replaced, and although this car has only done 48k miles, it's only done extremely short journeys all it's life (until now).  I guess the short journeys would potentially cause problems to the EGR though?

[Andy B]

Tech II can tell that engine to treat the EGR as though it's not fitted.

It certainly can, but I'm concerned that the EGR may not be the problem, or just part of the problem due to the O2 readings, or is this likely to be linked to an EGR problem?

There is no record in the SH of the Cat being replaced, and although this car has only done 48k miles, it's only done extremely short journeys all it's life (until now).  I guess the short journeys would potentially cause problems to the EGR though?

I just thought that it would remove the EGR completely from the equation 

[Marks DTM Calib]

On a petrol car the EGR should be closed at idle and on full throttle.

If its leaking slightly the it will effect idle.

On that model, the EGR position is deteced via the MAF and hence the position figure is not that accurate.

You can buy a blanking gasket from Vx which will prove if its at fault.

[Broomies Mate]

UPDATE:

I have removed and cleaned the EGR and replaced it with a new gasket (as it left the factory). I reset the Fault Code and tested the EGR valve off the car. The plunger actuates just as it should. All put back together and the car drove 10-15miles fine, then the EML illuminated again, Fault Code P0400.

I then removed the EGR again, make a plate from 3mm Steel, bolted the plate and EGR in place but swinging the EGR out of the way so it is in open space. Reset the Fault Code and took it for a drive. Exactly the same, within 20 miles the EML Illuminated again.

So, the EGR actuates fine but still reporting a fault.

Any more thoughts on how to rectify this problem?

The only other thing I did when working on the car was to clean the throttle body and do an oil & filter change which has increased throttle response, but still have a massive flat spot under 2k RMP. I know these engines need to be revved to get any performance out of them, but this car is IMO dangerous when pulling out of junctions. I understand it is difficult for me to draw an accurate comparison as my daily car has over twice the CC of this little 1600, but my work Transit is quicker off the mark than the Astra.

New plugs and coil-pack fitted a couple of months ago.

[tidla]

have a look round here

http://www.bba-reman.com/forums/

before you post, make sure you put all the facts as they are not always as friendly as here..