Bit of a chock today, my 2019 Focus just failed its inspection due to high emission readings.

Just had my first big service at 36k miles (58000km), replacing air filter, spark plugs and oil/filter at authorized Ford Dealership.

The guy testing was really nice and did a couple of more laps, high revs to get the engine hot - no improvement.

 

Readings were:
CO 0.8 (0.3)

HC 4 (200)

CO 2500 1.4 (0.2)

Lambda 0.97

 

Any ideas what might cause this and what the cost might be? Faulty sensor? Car has been a bit more thirsty lately, but nothing excessive, noticed this after doing a 8h trip. I have noticed a stronger smell of exhaust after a drive after exiting the vehicle. Did not think anything of it, noticed the same smell on other newer Fords.

Was it a Ford dealership?

If not, contact your nearest Ford dealer and ask if there's a PCM update available to correct the emissions on your car.

3 minutes ago, TomsFocus said:

Was it a Ford dealership?

If not, contact your nearest Ford dealer and ask if there's a PCM update available to correct the emissions on your car.

Yes, Ford dealership. 

One thing to mention is that the car passed MOT last year with good emission values - only done 600 miles since then.

Ah, fair enough.  Another member failed their first MOT for the same thing within the past month so was worth an ask.

The extra strong exhaust smell could be down to a GPF regen.  They work slightly differently to a diesel DPF regen but still ultimately burn soot in the exhaust which creates more smell at that time.

The HC's are fine.  Lambda is a bit rich but still just within MOT tolerance.  So it's mainly the CO reading that's the problem.  That on its own usually does suggest a worn cat, but that seems unlikely on a 5 year old car, especially if it was fine 12 months & 600 miles ago.

Usually we'd suggest a spark plug change for a cleaner burn, but as that's been done, I'm struggling to think of a reasonable suggestion in this case.

Do you use cheap fuel out of interest?  Could try a bit of premium if so.  Though I'm not convinced that'll make a big enough difference.

It could be a fault with a lambda sensor but generally they'd trigger a dash warning.  I wouldn't like to recommend any sensors without further diagnostics or some fault codes really.

Hopefully other members have some better ideas.

Just now, TomsFocus said:

Ah, fair enough.  Another member failed their first MOT for the same thing within the past month so was worth an ask.

The extra strong exhaust smell could be down to a GPF regen.  They work slightly differently to a diesel DPF regen but still ultimately burn soot in the exhaust which creates more smell at that time.

The HC's are fine.  Lambda is a bit rich but still just within MOT tolerance.  So it's mainly the CO reading that's the problem.  That on its own usually does suggest a worn cat, but that seems unlikely on a 5 year old car, especially if it was fine 12 months & 600 miles ago.

Usually we'd suggest a spark plug change for a cleaner burn, but as that's been done, I'm struggling to think of a reasonable suggestion in this case.

Do you use cheap fuel out of interest?  Could try a bit of premium if so.  Though I'm not convinced that'll make a big enough difference.

It could be a fault with a lambda sensor but generally they'd trigger a dash warning.  I wouldn't like to recommend any sensors without further diagnostics or some fault codes really.

Hopefully other members have some better ideas.

 

Thanks for the response.

I looked at the checklist after the service and I cannot see any mention of system update or PCM, I do not think they updated it if that matters. 

I do not use cheap fuel and i filled the tank up right before MOT. I've checked OBD, no error codes - but it's a cheap scanner.

PCM updates aren't carried out as part of a service.  Only if there's a safety recall on the car.  For a non safety related issue it will only be updated if the customer complains of a fault.  It will cost around an hours labour if they do it.  I would have expected them to check after it failed MOT but obviously no way of knowing whether they did.

Again, they won't scan for fault codes unless instructed to do so.  That'll cost you another hours labour.  We recommend using Forscan on here which is very similar to the full dealership tool and will pick up Ford specific codes.  As there haven't been any warning lights or messages on yours, there may not be any codes stored.

On 5/7/2024 at 6:39 PM, TomsFocus said:

PCM updates aren't carried out as part of a service.  Only if there's a safety recall on the car.  For a non safety related issue it will only be updated if the customer complains of a fault.  It will cost around an hours labour if they do it.  I would have expected them to check after it failed MOT but obviously no way of knowing whether they did.

Again, they won't scan for fault codes unless instructed to do so.  That'll cost you another hours labour.  We recommend using Forscan on here which is very similar to the full dealership tool and will pick up Ford specific codes.  As there haven't been any warning lights or messages on yours, there may not be any codes stored.

Just got the call from the garage. It was a sensor, he didn't specify which and my 1 year old was screaming in the background so I forgot to ask. If I understand correctly, it will be covered under warranty (even though my car is 5 years and 1 month...).

They had seen 2 cases of this with the MK4's and a couple of other cases with "the other sensor" (guessing lambda?).

I'll come back with the specifics once I pick it up from repairs.

So, the garage changed my O2 sensor and I was back doing the MOT again. Failed.

Waiting for the callback. They let me look at the emission sensor values and it was all over the place. It went from being good, to being really bad (1.2) then back to being perfect again, like it was fluctuating. My mind instantly thought "bad sensor", but according to the garage they tested all that.

On 5/7/2024 at 6:39 PM, TomsFocus said:

PCM updates aren't carried out as part of a service.  Only if there's a safety recall on the car.  For a non safety related issue it will only be updated if the customer complains of a fault.  It will cost around an hours labour if they do it.  I would have expected them to check after it failed MOT but obviously no way of knowing whether they did.

Again, they won't scan for fault codes unless instructed to do so.  That'll cost you another hours labour.  We recommend using Forscan on here which is very similar to the full dealership tool and will pick up Ford specific codes.  As there haven't been any warning lights or messages on yours, there may not be any codes stored.

PCM update solved all issues - CO values are now at 0.01. So now I have a brand new (uneccesary?) o2/lambda sensor in a 5 year old car, and a newly updated PCM.

The annoying part is that my car history now shows up with two MOT failues which I guess will have an impact on resell value.

Do I have any right to be upset with the ford dealership for not spotting this right away? I have been very friendly and diplomatic throughout this whole process, but I must admit that it is pretty annoying that the cause was "just an update".

Could this have been caused by changing spark plugs / doing the "big service" or can it be linked to an actual event causing this?

34 minutes ago, FocusedAF said:

Do I have any right to be upset with the ford dealership for not spotting this right away?

Yes, I would make them fit the original sensor and refund the labour and cost for the new one.

The first thing they should do is check software levels, but they NEVER plug in

6 minutes ago, DaveT70 said:

Yes, I would make them fit the original sensor and refund the labour and cost for the new one.

The first thing they should do is check software levels, but they NEVER plug in

The only money I've spent so far is transportation to and from the dealership after leaving the car with them. The rest will be covered by insurance and I think the cost for me will be around 224GBP as deductible after the insurance has payed out.

1 hour ago, FocusedAF said:

PCM update solved all issues - CO values are now at 0.01. So now I have a brand new (uneccesary?) o2/lambda sensor in a 5 year old car, and a newly updated PCM.

The annoying part is that my car history now shows up with two MOT failues which I guess will have an impact on resell value.

Do I have any right to be upset with the ford dealership for not spotting this right away? I have been very friendly and diplomatic throughout this whole process, but I must admit that it is pretty annoying that the cause was "just an update".

Could this have been caused by changing spark plugs / doing the "big service" or can it be linked to an actual event causing this?

Thanks for letting us know the outcome.  Glad it's sorted now.  

 

I'm not sure what the cause is of the software glitch unfortunately.  It's not likely to be caused by a physical change such as spark plugs though.

Yes, I think it's acceptable to be upset with the situation.  Though if garages and Ford dealerships did their jobs correctly, this forum would be a much quieter place, so it isn't uncommon.  Obviously you can't get the MOT fails removed.  And if I'm reading correctly, it won't have cost you much in the end.  (I didn't realise car insurance covered this sort of thing, unless it's more like an extended warranty).  So I don't think there's much to be gained from arguing with them.  You could just use a different dealership in future.  Or you could try politely requesting some form of compensation such as a discount on the next service or a free MOT next year.  But you will need to explain why that is, as you have done here, MOT failures look bad during resale, having to spend money on additional transport, the inconvenience of not having your car with a young child etc.  They might give you something out of 'goodwill' for that.

4 hours ago, FocusedAF said:

The annoying part is that my car history now shows up with two MOT failues which I guess will have an impact on resell value.

Keep any documentation for work carried out.  Handy to show a buyer in future that fault was fixed.

I went to look at a Focus on 212,000 miles and asked if it had belt changed / clutch.  Seller said he can show me a picture on his phone of the belt being changed and "it drives like a new car so it must've had a new clutch".  Needless to say I walked away.

22 hours ago, TomsFocus said:

Thanks for letting us know the outcome.  Glad it's sorted now.  

 

I'm not sure what the cause is of the software glitch unfortunately.  It's not likely to be caused by a physical change such as spark plugs though.

Yes, I think it's acceptable to be upset with the situation.  Though if garages and Ford dealerships did their jobs correctly, this forum would be a much quieter place, so it isn't uncommon.  Obviously you can't get the MOT fails removed.  And if I'm reading correctly, it won't have cost you much in the end.  (I didn't realise car insurance covered this sort of thing, unless it's more like an extended warranty).  So I don't think there's much to be gained from arguing with them.  You could just use a different dealership in future.  Or you could try politely requesting some form of compensation such as a discount on the next service or a free MOT next year.  But you will need to explain why that is, as you have done here, MOT failures look bad during resale, having to spend money on additional transport, the inconvenience of not having your car with a young child etc.  They might give you something out of 'goodwill' for that.

No goodwill and no compensation except they payed for and did the MOT. Lambda value higher this time at 1,01 - the CO-values were at solid 0's.

Had a long talk with them regarding the situation and he insisted that the o2/lambda sensor had to be replaced - this according to him was not an uncommon fault in mk4. I asked, could the odb-warnings regarding the sensor not just be due to the PCM needing an upgrade and the sensor just receiving faulty values - hard no from him, it had to be replaced. According to him, newer Focuses do not need to have an PCM-upgrade when a new sensor is installed and "the only reason I needed a PCM-upgrade was to reset the values the sensor received" (i'm paraphrasing here).

 

I requested a detailed report on everything done since the only thing I received was a receipt- insurance company got the rest.

Hopefully this thread helps someone else! Cheers for the help and the discussion.

For lambda the perfect figure is 1.  So 1.01 is actually better than 0.97.  Anything less than 1 is excess fuel (rich mixture), anything more than 1 is excess air (lean mixture).  The acceptable range for MOT is 0.97 to 1.03.