Beginning to get concerned! (emissions fault returned)

[KeithS]

Knowing how easily issues can turn into major fiasco when it comes to ongoing problems, I was more than a little angry when after filling up my MG3 HYBRID, the supposed fixed 'Emissions fault' warning has returned.
Clearly there could be a more serious issue going on here...you have to wonder how many others have this problem, or the problem is waiting to begin!

 

[copilux]

similar problems occurred when the fuel cap was not properly tightened after refueling

 

[MG Clive]

I know you know all about the fuel cap trick Keith, but if the light has come on after filling up, it might be worth double, or triple checking it? When I filled mine up for the first time I gave it half a dozen clicks just to make sure.

 

[Hybrid Ann]

I was brought up not to over screw stuff, but it would seem that you have to over screw the petrol cap till you hear that awful over screw ’Clunk’. If your emissions light has been on, it can take a day or two to go off after. This did work for me. Not had the light on now for over two thousand miles and four months. I hope this helps.

 

[evor]

I had an MG HS for 6 month and the emission light came on after I had filled up to the brim, called the dealer they couldn't fit me in for 3 month. Had a read online and found articles around same issue but didn't work eventually was fixed by leaving cap off for 30 min replaced light went out.
Not sure if this is with all new cars or confined to MG but interesting to see that it may happen to my new MG3 as well.

 

[KeithS]

Thanks for the replies, and yep have tried the fuel cap trick previously without success. The software update that MG issued was supposed to fix this known fault, and as this hasn't worked the dealer will have to involve MG Technical when the car goes in next Thursday.
Also as I've said previously, there would appear to be a drop in fuel economy when the fault appears, so I do wonder if it has something to do with the Oxygen sensor which measures Emissions.
All told let's hope this doesn't turn into a merry-go-round of visits back to the dealer!

I had an MG HS for 6 month and the emission light came on after I had filled up to the brim, called the dealer they couldn't fit me in for 3 month. Had a read online and found articles around same issue but didn't work eventually was fixed by leaving cap off for 30 min replaced light went out.
Not sure if this is with all new cars or confined to MG but interesting to see that it may happen to my new MG3 as well.

Many thanks for your explanation. I actually tried your method on Thursday, and whilst the light didn't go out straight after, as with others who have recommended this idea, when I went back to the car on Sunday the light was also extinguished.
I have an appointment on Thursday with my dealer to investigate, so I'm wondering whether I should keep it, or cancel and wait and see...

 

[Hybrid Ann]

Exactly the same for me. Light on, tightened fuel cap, a few days later emissions light off. Three months later, never happened again….Sorted. I reckon you could cancel appointment.

 

[H11 RYB]

MG3 Trophy only 2 weeks old.... Fuel low light came on THEN Engine emissions alert..... Dealership saw it immediately... Said had "reset the UPV"?

 

[KeithS]

My dealership carried out a software update about a month ago. The light stayed off for a week, as soon as a filled the car the light was on again.
I have covered more recent events under 'Emissions fault warning light- AGAIN', but to let you know the car is back in and the dealer and seemingly MG Technical are not sure what's causing the problem. I'm wondering if it's the fuel cap, either way you will notice the fuel economy drops as the engine can't measure the fuel mixture properly.
Laughably the service advisor, who admitted he's not Technical suggested that they might give me the car back without fixing the problem, and then let me wait for MG to come up with a solution, as that seems to be what's happening with a problem on the new HS!

BTW did they mention. What UPV stands for?

 

[H11 RYB]

No.... I just assumed it was a software update...
Also, when driving in a 20 mph zone it recognised it as 115 mph ! Said they cannot "do anything" with this error....
When tank is full it shows 411 miles although the details stated a full tank should allow 500 + miles of travel...
ANY issue concerns me greatly as hubby chose and ordered the car. I took delivery the day before his major surgery for Pancreatic Cancer and he has not been able to drive it.
I am driving 90 miles daily to visit him and gave up my own 15 year old Honda Jazz (passed its m.o.t with no issues) for us to have one vehicle.
Hope we don't end up regretting it.
H11

 

[Hybrid Ann]

My car often shows speed as 100 etc when it reads a sign. Troubling.

 

[KeithS]

Another day, and my car remains at the MG dealer, with still no suggestion from MG Technical as to how to resolve the problem!!

 

[Hybrid Ann]

Not sure what to do about these problems. Would you legally be able to return the car all together. I’m getting pretty fed up with the intermittent problems I’m experiencing with this car.

 

[KeithS]

Sorry for not being up to date with what your experiencing, but what are the intermittent problems?
Has the Engine Emissions fault returned?

 

[Hybrid Ann]

laptopSpeed signs show 100,80 in a 30 or 50 zone then normal then not, Sudden loud electrical ping/sound sometimes with the engine off or on, also other odd sound.at intervals. I try to put regen use on steering wheel star and it won’t let me. A few problems to say the least, quiet apart from the MG mechanic scratched my dashboard with his laptop and MG Manager said they would fix it, and I’ve never heard from them even after a trip there. Rubbish service! Very disappointing.

 

[KeithS]

laptopSpeed signs show 100,80 in a 30 or 50 zone then normal then not, Sudden loud electrical ping/sound sometimes with the engine off or on, also other odd sound.at intervals. I try to put regen use on steering wheel star and it won’t let me. A few problems to say the least, quiet apart from the MG mechanic scratched my dashboard with his laptop and MG Manager said they would fix it, and I’ve never heard from them even after a trip there. Rubbish service! Very disappointing.

The speed limit display is something I have experienced very occasionally, but I would say this feature should not be relied as they are inherently inaccurate with them sometimes mis-identifying or not identifying roadside speed limits at all. I use a Road Angel Speed camera warning device, and whilst I pay for an annual subscription it often doesn't update correctly on smart motorways, and my other car sometimes fails to see speed limit changes on the motorway overhead gantries.
Given the shear number of cash registers (speed cameras!), I am always watching for the signs myself and not relying on the car!
The after sales situation is I agree pretty poor, and it's almost as if MG UK see themselves as a budget brand and as such feel it's OK to provide a budget service. I would persevere with regards the electrical sound issue, and the dashboard scratch, as I think a lot of dealers think the customer will just forget about it.
As it is I am still waiting for my car to ge fixed, and it's been in the service department since almost the beginning of the week with no progress updates!

 

[KeithS]

I got my car back yesterday, and so far no return of the Emissions warning. More software updates were carried out, this time centering around the EGR sensor (Oxygen sensor).
On a different note the colder weather and I think with use of the heater introduced an annoying rattle from somewhere in the dashboard!

 

[MG Clive]

I wish you the best of luck with your emissions warning light @KeithS, I hope it never comes on again. ?

 

[mjl engineering]

Knowing how easily issues can turn into major fiasco when it comes to ongoing problems, I was more than a little angry when after filling up my MG3 HYBRID, the supposed fixed 'Emissions fault' warning has returned.
Clearly there could be a more serious issue going on here...you have to wonder how many others have this problem, or the problem is waiting to begin!

Hi Kieth. I am currently going through this issue on a car in my workshop. It shows up as a P0402 EGR code when tested. No faults running live data, no faults. It seems like something to do with fuel levels in the tank. If you have any luck with a reason please share. The mg dealers here don't really know either. The car has only 3500km on it.

 

[Hybrid Ann]

When you do up the petrol cap be sure to over close it so you hear an uncomfortable clank. Then wait a day or two for the warning light to go off. I did this and never had that problem again.