The Mégane II Owners' Club

Hi,

friend of mine has a 2005 Megane convertible 1.6 petrol.

it failed the MOT on emission, the reasons are

Exhaust emissions carbon monoxide content after 2nd fast idle excessive (7.3.D.3)
Exhaust emissions hydrocarbon content after 2nd fast idle excessive (7.3.D.3)
Exhaust emissions Lambda reading after 2nd fast idle outside specified limits (7.3.D.3)

E.M.L is on and garage advised the REAR & FRONT Lambda sensors need replacing,

Does this sound like it is the Lambda sensors are faulty and need replacing ?

just to add i noticed his outside temp displays lower than what it should. eg its 7c out but will display -3c etc if that has any help

hope you can help on here

I doubt its both sensors to be honest.
Do you have any codes that you can provide?

Sounds like a certain garage that sounds like qip fit

before the MOT there was 4 fault codes when i plugged my diagnostics in, but cant remember the codes off the top of me head (i have to ask my mate as he wrote them down), i remember seeing O2 sensor fault for 2 of them im sure bank 1 & bank 2 came up. and 1 was for camshaft sensor, but i cant remember the other ones. what i done was erased all the codes and went for a test drive and the EML stayed off (car had been driven 30mins before codes were erased), he said the next morning the EML came back on thats when he had to take it for MOT,

i havnet had the chance to read the faults again yet,

What I did notice when I went for the test drive with him I could smell petrol,like it was running rich.

Running rich is probably the most likely answer.
Now what would cause that?

Dodgy Cam sensor, dodgy coils, dodgy plug, etc.
So without some other testing and codes its' hard to say but one thing is for sure.
GO TO ANOTHER GARAGE! Replacing both O2 sensors will not fix this issue.

Is it missing at all?

When he took me for a test drive I didn't notice any misfire just the strong smell of petrol. But now saying that I think that other code was a misfire on cylinder 3 I'm not 100% sure. I need to read the EML again and see what it comes back with tbh. It's find of good knowing changing the lambda sensors won't fix the emissions and it could be something cheaper

Any updates?