MOT advice

[Barby14]

Could anyone explain what these MOT failures mean and how they could be fixed and the potential costs:

Engine MIL inoperative or indicating a malfunction.
Exhaust carbon monoxide emissions at idle exceeding the manufacturer's specified limits.
Exhaust lambda reading after the second fast idle outside the manufacturer's specified limits.

Thanks in advance

[Richard-D]

Barby14 said:

Could anyone explain what these MOT failures mean and how they could be fixed and the potential costs:

Engine MIL inoperative or indicating a malfunction.
Exhaust carbon monoxide emissions at idle exceeding the manufacturer's specified limits.
Exhaust lambda reading after the second fast idle outside the manufacturer's specified limits.

Thanks in advance

There's no way to know the potential costs to sort as that could be anything from a slight hole in the exhaust to an engine requiring replacement.

Essentially those 3 faults likely have a single cause but there's no way no know what that is without further investigation.

Also, wrong section of forum, I'm sure it'll be moved to 'technical' soon enough.

[Barby14]

Thank you. I couldn’t find where to put it!

[Super Sonic]

I think what this car needs is a diagnostic test which involves plugging in a diagnostic tester which will basically identify any faults, to put it simply. This will give you a better idea what work needs doing. At a guess I would say it needs a new lambda sensor, which 'smells' the exhaust gas.

[Doesitdrive]

It needs a new lamba sensor. And the EML turned off after fitting it.

Seen this loads on the part ex sheds. The failed Lamba is messing with emissions and flicking on the EML.

[M4cruiser]

Agree lambda sensor is most likely.
But don't overlook the basics. Has it been serviced?
A bad air filter and spark plugs can also cause emissions fail.

[E-bmw]

It COULD be a lambda sensor but let's be honest, the great vast majority of "Lambda sensor" issues are actually that the Lambda sensor has detected an issue rather than is causing an issue.

Things to check first.

Air leaks into the inlet after the MAF.
Exhaust leaks.
Oil & filter change if it is due.
Air filter if it is mucky.
Check spark plugs & change if in poor condition.

But before you spend any money get the codes read as they may well tell you EXACTLY what it is rather than guessing.

[stevieturbo]

fix the warning light, scan the ecu to see if it is unhappy and why.

Also in terms of emissions, post the full test sheet results.

[rufturbo]

If the MOT test gas analyser detected carbon monoxide then the catalytic converter isn’t working efficiently. The lambda sensor only monitors fuel AFR so the ECU can adjust fueling. Exhaust gas is carbon monoxide, the CAT converts it to carbon dioxide so that no carbon monoxide should be sniffed out of the exhaust pipe.

[richhead]

E-bmw said:

It COULD be a lambda sensor but let's be honest, the great vast majority of "Lambda sensor" issues are actually that the Lambda sensor has detected an issue rather than is causing an issue.

Things to check first.

Air leaks into the inlet after the MAF.
Exhaust leaks.
Oil & filter change if it is due.
Air filter if it is mucky.
Check spark plugs & change if in poor condition.

But before you spend any money get the codes read as they may well tell you EXACTLY what it is rather than guessing.

I see this miss information posted alot on here, a code read will not tell you EXACTLY what is wrong, it will give a clue to an experienced mechanic, nothing more

[DaveF-SkinnysAutos]

What car? Sounds like a classic petrol Mini MOT failure list?

[E-bmw]

richhead said:

E-bmw said:

It COULD be a lambda sensor but let's be honest, the great vast majority of "Lambda sensor" issues are actually that the Lambda sensor has detected an issue rather than is causing an issue.

Things to check first.

Air leaks into the inlet after the MAF.
Exhaust leaks.
Oil & filter change if it is due.
Air filter if it is mucky.
Check spark plugs & change if in poor condition.

But before you spend any money get the codes read as they may well tell you EXACTLY what it is rather than guessing.

I see this miss information posted alot on here, a code read will not tell you EXACTLY what is wrong, it will give a clue to an experienced mechanic, nothing more

What about my post is mis-information?

Are you trying to tell me that all lambda sensor fault codes ARE in need of a new Lambda sensor?

Next you will be trying to tell me all MAF fault codes are in need of a new MAF.

[richhead]

E-bmw said:

richhead said:

E-bmw said:

It COULD be a lambda sensor but let's be honest, the great vast majority of "Lambda sensor" issues are actually that the Lambda sensor has detected an issue rather than is causing an issue.

Things to check first.

Air leaks into the inlet after the MAF.
Exhaust leaks.
Oil & filter change if it is due.
Air filter if it is mucky.
Check spark plugs & change if in poor condition.

But before you spend any money get the codes read as they may well tell you EXACTLY what it is rather than guessing.

I see this miss information posted alot on here, a code read will not tell you EXACTLY what is wrong, it will give a clue to an experienced mechanic, nothing more

What about my post is mis-information?

Are you trying to tell me that all lambda sensor fault codes ARE in need of a new Lambda sensor?

Next you will be trying to tell me all MAF fault codes are in need of a new MAF.

my bad i quoted the wrong post, what you say is correct

[E-bmw]

richhead said:

E-bmw said:

richhead said:

E-bmw said:

It COULD be a lambda sensor but let's be honest, the great vast majority of "Lambda sensor" issues are actually that the Lambda sensor has detected an issue rather than is causing an issue.

Things to check first.

Air leaks into the inlet after the MAF.
Exhaust leaks.
Oil & filter change if it is due.
Air filter if it is mucky.
Check spark plugs & change if in poor condition.

But before you spend any money get the codes read as they may well tell you EXACTLY what it is rather than guessing.

I see this miss information posted alot on here, a code read will not tell you EXACTLY what is wrong, it will give a clue to an experienced mechanic, nothing more

What about my post is mis-information?

Are you trying to tell me that all lambda sensor fault codes ARE in need of a new Lambda sensor?

Next you will be trying to tell me all MAF fault codes are in need of a new MAF.

my bad i quoted the wrong post, what you say is correct