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I know there are a lot of threads on this and I've been reading them for weeks trying to find a situation like mine.
I have had an Alfa GT 1.9JTDM Lusso for about a month, 120k miles. Its had quite a lot of work over the past year including new turbo, clutch, EGR, water pump and timing belt.
From when I bought it when the engine is turned on I get the MCSF error, using and ODB2 plus torque pro I found out Its the P0401. The first thing I tried was an ECU reset, this didnt clear the fault straight away but it dissapeared the next day only to return 2 days later. I was told that the EGR might have been faulty (even though it was fairly new) so, with advice from a 156 owning friend I replaced the EGR with another new one.
This also didnt remove the error message, but it did seem to improve power under 2k revs.
I've tried clearing the fault (didnt work at all) and doing another ECU reset (yet again didnt clear the message straight away but it did dissapear the next day only to return 2 days later).

Where do I try next, MAF, MAP, turbo pipes?

Just a note, the MCSF error has never appeared whilst driving, it only ever appears when I first start the engine during the power-on self test, is this relevant?
 

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Blank the egr (£10 and 20mins) and just live with the eml light or have it mapped out for about £100. If DIY take care with the aluminium threads and invest in a new gasket as well. It's not doing any harm having the exhaust gas re-circulation low code and it can go away long enough for a mot. If you must: mapping will still save money as the valve never functions as it should for more than about 20,000 miles. Once blanked you'll never worry about it again and any future boost issues or power loss can't be attributed to it so the diagnosis of future troubles becomes easier. Your inlet manifold will also be protected from all that tar and soot. Can't really think of any downsides to blanking apart form increased NOx emissions which don't concern me.
 

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Discussion Starter #3
Blank the egr (£10 and 20mins) and just live with the eml light or have it mapped out for about £100. If DIY take care with the aluminium threads and invest in a new gasket as well. It's not doing any harm having the exhaust gas re-circulation low code and it can go away long enough for a mot. If you must: mapping will still save money as the valve never functions as it should for more than about 20,000 miles. Once blanked you'll never worry about it again and any future boost issues or power loss can't be attributed to it so the diagnosis of future troubles becomes easier. Your inlet manifold will also be protected from all that tar and soot. Can't really think of any downsides to blanking apart form increased NOx emissions which don't concern me.
I may have the EGR blanked at some point. For now I'd like to find out why and where the error is coming from. It can't be the EGR itself as its only a few days old. The appearance of the error could mean there is a problem with MAP, MAF or some feeder pipe somewhere.
I'd kind of like to know where the problem actually lies :)
 

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I may have the EGR blanked at some point. For now I'd like to find out why and where the error is coming from. It can't be the EGR itself as its only a few days old. The appearance of the error could mean there is a problem with MAP, MAF or some feeder pipe somewhere.
I'd kind of like to know where the problem actually lies :)
You will feel a loss in performance when MAF or MAP fail. But diagnosis is so much easier once the egr is eliminated as a cause. Having just fitted a new egr offers no certainty that it is functioning correctly. The code suggests it is not opening.

Blank it off. Go for a drive. Does the car feel good and is smoke free? P0104 can be ignored.
 

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The ecu works out if there is flow through the egr valve by looking at readings from the maf and map sensor, p0401 is insufficient flow tnrough the egr valve but if the valve is clean and opening properly then if either the map or maf sensor is giving incorrect readings it can trigger a fault.
The map sensor is in the back of the inlet manifold and they can often block up with gunk from the egr valve, try taking it out and clean it.
Also have a look at the inside of the inlet where the egr attatches, if the inlet is really badly gunked up it could be blocking the flow from the egr.
 

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Your car may have a serious fault but start with the cheap, easy and common fixes first. It's quite probable that you don't need a new MAF, MAP, turbo, actuator or manifold!

New vacuum hoses for vnt solenoid £5.
Blank egr £10.
Check turbo actuator moves.
Clean MAP sensor.
Check for splits in turbo hoses and unmetered air after the air box.

In most cases these easy and cheap tasks will restore performance. Don't waste time or money investigating elsewhere until you've spent £15 and an hour of your time on this. A working egr just makes things more complicated than they need to be.

If the car is running well and the only code is p0401 then all is good.
 

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The EGR valve might be new but it isn't going to open if the electrical connection is faulty. You need to check the valve operates using the test function of the OBD software. Just run the test and you should hear it clicking as it cycles open/closed.

Course the other possibility is someone has had the EGR mapped out of the ECU incorrectly, so the valve doesn't open but the ECU still throws a fault. I'm sure someone else on here had the same problem after a remap recently.

The P0401 fault usually takes a couple of days to appear after you blank it or pull the electrical connector to stop it opening. Takes a number of cycles where the MAF flow doesn't drop when the EGR is supposed to be open before the ECU decides it isn't opening properly ... and tells you the next time you start the car, not when you're driving.
 

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Discussion Starter #8
The car seems to be running absolutely fine. I just wanted to find out why the error was appearing.
As far as I know it hasn't had a remap. Any way to find out?
 

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In multiscan you can look at the opening % of the egr valve, you would need to get a passenger to watch it whilst you are driving to see if the ecu is calling for it to open.
As I found out when I had problems with my remap by motormech just switching the egr off in the ecu isnt enough, it needs to be reprogramed to not look for the flow as well, it took them ages to work this out as they didnt have a clue.
 

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Discussion Starter #11
In multiscan you can look at the opening % of the egr valve, you would need to get a passenger to watch it whilst you are driving to see if the ecu is calling for it to open.
As I found out when I had problems with my remap by motormech just switching the egr off in the ecu isnt enough, it needs to be reprogramed to not look for the flow as well, it took them ages to work this out as they didnt have a clue.
I have torque pro so I should be able to check this. What values should the EGR be running between?
 

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Mine is constantly showing 4% and as it is disabled doesnt change.
You would expect the figure to change when accelerating and decelerating if it is working normally..
 

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Did you actually clear the fault from the ECU after replacing the EGR? If left it will take 5 or 6 restarts before it disappears of its own accord.
 

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Don't replace the egr; blank it! On the 8v the eml will remain clear on the dash long enough to pass the mot and if you still have the engine cover the tester will be non the wiser about your environmental crimes against humanity.

Sent from my BBB100-2 using Tapatalk
 

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Did you actually clear the fault from the ECU after replacing the EGR? If left it will take 5 or 6 restarts before it disappears of its own accord.
Yes I did clear it but it came back next day.

I have been driving it since then atleast a couple of weeks now there is a very minimal improvement in black smoke but I can see the intermittent power loss under acceleration at low speed under 2000 rpm is still there.

Any advise?

Do I need to clean / replace MAF sensor?
 

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You need to read the MAF sensor out when you drive the car, because they arnt cheap to replace.
Would be a waste of money when you replace a good one.
Not fund of cleaning them, because that can damage the sensor.
 
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