Bought a 2ltr focus tdci been sat for a while. Took it for MOT and failed on emissions, got around a 2 on average. Did a cataclean and got a retest and it’s on around a 1. Gunna clean the map and egr and hope this solves the issue, if not any advice? 

6 minutes ago, DaleS30 said:

and failed on emissions, got around a 2 on average.

On 12/12/2025 at 9:19 PM, unofix said:

How the Lambda Sensor Affects the MOT

• Emissions Test: While petrol cars have specific lambda readings taken during the gas analysis, diesel vehicles undergo a smoke opacity test. However, the lambda sensor's primary role in both types of engines is to help the engine control unit (ECU) regulate the air/fuel mixture for efficient combustion and to reduce harmful pollutants.

@TomsFocus may have some ideas

This engine won't have a lambda sensor.

Also sounds like someone's doing the wrong test for this car.  Pre-2008 turbo diesel pass is 3.0 OR the plate value, whichever's lower.  But the plate value is unlikely to be less than 2, it certainly won't be 1.

Can you please post up the test sheet so we can see exactly what test they've run on this car?

 

46 minutes ago, TomsFocus said:

This engine won't have a lambda sensor.

Also sounds like someone's doing the wrong test for this car.  Pre-2008 turbo diesel pass is 3.0 OR the plate value, whichever's lower.  But the plate value is unlikely to be less than 2, it certainly won't be 1.

Can you please post up the test sheet so we can see exactly what test they've run on this car?

 

 

Just now, DaleS30 said:

 

That was the second test it won’t let me upload the 1st but that was at a 2 

27 minutes ago, DaleS30 said:

 

Thanks.  Plate value of 0.51 must be incorrect.

Can you find the plate on your car to confirm what it should be?  Usually it'll be on a sticker just inside the driver's door.  Will be in the format of 'X.XX'.

Adding to the above post, I noticed the reg number is visible on that sheet.

Having checked it I can see that this is a DPF model, so the plate value will be lower than I first thought.  The earlier 2.0 TDCI's didn't have a DPF so you are unlucky with this one.

However, it's still only Euro 4, and I'd be very surprised if they had such a low plate value at that time.

Don't want to advise any further unless the plate value can be confirmed.

If the plate value happened to get damaged and wasn't readable it has to be tested at the higher limit of 3, seat belts get trapped in doors and things unfortunately. 

As it's now been tested they have to use the plate value for retest but if you presented it again for a full test they would test it at 3.