[SCGT]

Ok ......yet another P0401 thread.

Swapped EGR / Cleaned MAP , MAF not checked as was replaced last year. Up until this week engine management light popped on every 4/5 weeks (P0401).....got into the nasty habit of simply deleting it with OBD Reader ...

Now comes on 1/2 hrs after delete .......

Admittedly GT is overdue a service , done about 14k since last one .........could it simply be telling to go get it done?

 

[pubsinger]

Can't see it being the MAF. P0401 is the MAP not detecting the change in pressure in the inlet manifold when the EGR opens. I think.

If you've got MultiECUScan, unbolt the EGR but leave the electrical connector attached and check it's operating smoothly with the actuator test. If the EGR is OK I'd guess it's a faulty MAP.

All the best

Pub

 

[sussexa]

if p401 is insufficient egr flow, and your not blanked or using restricted gaskets there is always a chance that the egr cooler could be partially blocked restricting flow.
im pretty sure it uses maf to detect egr flow, can you get any readings off maf with fes or alfadiag etc with egr operating and not operating.

 

[SCGT]

Mmmm. ...do have a restricted gasket , wonder if the tropical heat outside I'd anything to do with it? ...possible MAP is faulty as its been in and out a good few times and the sensor looks swollen! ...might try a new one ! Seen an aftermarket one on flea bay for £15...assume not worth buying?

 

[SCGT]

Driving Me Insane Now .....ARRRGGGGGGGGGGGGGGGGGGGGGG

GT was in for full big service everything , belts the lot ....got a diag done and P0401 cleared (again) MAF recalibrated .......stripped out EGR (again) cleaned so good you could eat your dinner off it , checked electrics and pin movement , replaced MAP with a new one ........................ lasted two days ........ITS BACK P0401. So next guess is a new MAF !!!! .........Is this an easy job and recommendations for a new MAF please , something cheaper than the BOSCH if possible ....(or is it worth trying to clean?) ...I'm told not !!!! MAF was replaced about 2 yr ago by previous owner to they fail regularly ?

 

[pubsinger]

MAF was replaced about 2 yr ago by previous owner, do they fail regularly ?

Mine's original, 7 years and 115,000 miles old. The MAF on the GT JTD is a sealed unit, the sensor cannot be removed to clean, I managed to prise the grille out of one of the sides and gave the sensor a good spray with contact cleaner, it was filthy, kept spraying till it ran clear. That was a couple of years ago.

Have you (or the garage) removed the single hole EGR blanking plate?

Pub

 

[SCGT]

Have you (or the garage) removed the single hole EGR blanking plate?

Pub[/QUOTE]

That's a good idea , plate is still in place , I did take it out before and cleared EML and it ran ok for a few days. I put it back though ! ...thinking its better to have it in place..! dont know if I have a gasket ! ....should I run without gasket?

 

[pubsinger]

Yes, there should be a gasket on both sides of the EGR.

The square restrictor gasket on the manifold side replaces the original, the oval restrictor gasket on the feed to the EGR is used in addition to the original, or at least, that's how I've fitted mine.

Pub

 

[SCGT]

Fingers crossed ....restrictor plate removed (don't have a gasket gasket - will need to get one) , EML reset , went for a short drive (engine at full temp) ....ok at the moment but pattern has been 40 mile and ding ! ....see what happens tomorrow! ...Little screws for the fusebox/reader connector are getting very tired

 

[SCGT]

That's a good idea , plate is still in place , I did take it out before and cleared EML and it ran ok for a few days. I put it back though ! ...thinking its better to have it in place..! dont know if I have a gasket ! ....should I run without gasket?

well the fifty mile journey today did NOT throw up the EML ....however in 5th/6th I am getting a bit of hunting around 70mph ...dropping a gear resolves , so it's back to the drawing board..! (or maybe its the missing gasket?) ....have ordered one from eBay ! ...

 

[SCGT]

Getting very very angry now .....just went to the shops EML came ON. Ran a check and I now have codes 0235 & 0069....looks like my £14.99 MAP from eBay has already failed and turbo kicked in an error as I slammed my foot on accelerator in anger ....Cleared EML put Bosch MAP back in ...........lets see what happens tomorrow ..

 

[mr-mac]

Also clean/grease vgt actuator arm as a slight sticking here would make those errors pop up occasionally if it doesn't switch to big turbo mode quite as smoothly and quickly as it should...

Defo a regular clean and lubricate should on list of things to do once in a while.

John

 

[SCGT]

The plot thickens .....GT is driving like a shed . Anything over 50mph foot off gas then touch gas it feels like its going to cut out ....no EML. Happened this morning on way to work and so bad coming home that I had to exit motorway in case I ground to a halt. Got home put restrictor plate back in .....all is well , other than I know EML will come back on tomorrow with P0401. The MAF was calibrated 2 weeks ago with plate in place so me thinks that it does not like the fact that plate has been removed. Seriously doing my head in now ! Thanks for everyone's input on this ongoing nightmare your advice has been great as always ....Think it's back to CM Garage on Thursday morning , was thinking off cleaning actuator as mr-mac suggested but I am not clever enough for that one ... ....Feel a new MAF coming on , and i'm not buying an aftermarket one ........I've learned my lesson!...Off out for a curry and a few beers ..........a good few beers .........tomorrow I will wait with anticipation for that MCSF ping .................

 

[SCGT]

Today's result ....plate back in place , 50 mile round trip , no eml ........back to normal , ahh ...the fun of alfa ownership

 

[Alfa homie]

It sounds like the maf is on its way out. On my `04 156, the maf fails quite regularly, it is actually a consumable (a very expensive one for that matter).
Both times I fitted pureburg (car now nearly 96k miles). A bit of a flatt spot round 2200 rpm, but no biggie.

Speaking of restrictor plates, any ideas what the part number is? I have the square one, but I think its a good idea to fit the oval as well.

Good luck with your adventure.

 

[pubsinger]

Speaking of restrictor plates, any ideas what the part number is? I have the square one, but I think its a good idea to fit the oval as well.

Gasket Thread

Good Luck

Pub

 

[mr-mac]

Look on ebay for astra egr restrictor you'll find plenty of the cheapest ones and remember you need a std gasket for either side of it too

 

[Alfa homie]

Great thank you gents. I take it these will fit both my 156 and my wife's 147?

something I noted in the link. I have fitted the square restrictor plate without gaskets either side as I think that the orange part is the gasket! I might be wrong. Good thing I kept the old gasket

 

[mr-mac]

The older rectangle restrictor need the original gaskets, the newer one iirc orange round edge and metal in middle doesn't.

Yes 147 and 156 the same if not done do an egr clean as well, if quite old (the egr), then look for guide in here as it shows you how to take slider pin out, clean and lubricate as it's often the pin that starts to stick in egr. So a full clean, lubricate then gaskets should keep it running sweet for some time

 

[Alfa homie]

Nice one. thanks v much for info :thumbs: