Mondeo Mk2 failed MOT

gamingboy

Well-known Member
Hi, kind of stressed. I'm hoping for some advice.

The car failed today on emmisions.

"Exhaust emissions carbon monoxide content at idle excessive."

The car failed on a high CO level. It's suppose to be <=0.3&#37;, but mine was 0.46% on first test and 0.43% on the second.

The car does have a misfire at acceleration (hesitation). So i'm guessing that's the ignition leads, as it's not happening when just sitting at lights.

Would this cause the high CO and cause a fail? Or would it be the Lambda and/or Catalytic Converter?

Cheers for any help!
 

Badger0-0

Member
Rich mixture could indicate the Lambda, but more likely it's just in need of a full service.

I had exactly the same symptoms as you, perfect idle, but hesitation that I thought was weak fuelling at gentle around town driving. A service sorted it and it was just an iffy plug, at a guess, although, I had the belts changed and tappets done etc.
The mechanic I spoke to, said it was most likely electrical, as on my car (Rover 620) the EFI never goes wrong.

A bit of an eye-opener really, as it made me realise that modern cars can run pretty well, even with an intermittent misfire.

Trouble is, leads are stupidly expensive now. A set for a Mini used to be a fiver, but now I paid £25 for one :eek:

Point is, you have to get the basics sorted first.

IMO, change the plugs first. If that doesn't sort it, do a resistance check on the leads. Change any that don't seem right. Then change the Lamda.
 

NWhiteley

Active Member
If it was the Lambda sensor faulty, the HydroCarbons (HC) would probably be high as well. If the car has a missfire the HC's will almost always be high, as HC's are unburnt fuel in the exhaust gases.
If its just the CO that is high, its probably the cat at fault.
It is advisable to do the cheapest things first though... oil and filter change, renew the plugs, fit new HT leads, change the air filter, and if these dont cure the high emmisions, look at changing the Lambda and Cat.
 

gamingboy

Well-known Member
Hi, cheers for the replies.

The cat was changed a few months ago.

Also the car was serviced shortly after.

Ah cars. Too much hassle. :)


As a side note the test did say the lambda was a past.

lambda limit is 0.95-1.09 and mine was 1.01.

The HC is <=200PPM and min was 49PPM (1sttest) and 66PPM (2ndtest)
 

NWhiteley

Active Member
Hi, cheers for the replies.

The cat was changed a few months ago.

Also the car was serviced shortly after.

Ah cars. Too much hassle. :)
Who did the Cat? A lot of places are fitting cheap crapping cats, that are not efficient enough to reduce the emmisions to MOT standards. Get the garage to replace it under warranty, but make sure they fit something like a Timax (Bainbridge/Arvin).
 

gamingboy

Well-known Member
You're not going to like the answer. Neither do I now though.

Kwik-Fit fitted it and now i'm seeing people complaining about them.
 

NWhiteley

Active Member
You're not going to like the answer. Neither do I now though.

Kwik-Fit fitted it and now i'm seeing people complaining about them.


Kwik-Fit are one of the companies who used to fit these cheap cats, Take it back to them and get them to change it as detailed above. Take the MOT failure sheet, the VT30, with you, so there are no arguments. They give a 2 year warranty i believe.
 

gamingboy

Well-known Member
Thanks again for the advice guys and sticking with the replies. Do they stock the better Cats then, or is it going to be hassle?

The garage the MOT center sent me to did point to the Lambda and claimed it was "slow swiching".

Hence why I posted here for some advice. Want to get my facts straight and feel like I should not trust this MOT garage. Even if you get a free retest.
 

NWhiteley

Active Member
Thanks again for the advice guys and sticking with the replies. Do they stock the better Cats then, or is it going to be hassle?

The garage the MOT center sent me to did point to the Lambda and claimed it was "slow swiching".

Hence why I posted here for some advice. Want to get my facts straight and feel like I should not trust this MOT garage. Even if you get a free retest.
How slow is the slow switching? The Lambda sensor diagnosis machine we use shows a full switch, from one side of the gauge to the other and back again, in about 1.5 to 2 seconds. Usually, if the L.S. has failed, the sensor doesnt switch.
 

Badger0-0

Member
Thanks again for the advice guys and sticking with the replies. Do they stock the better Cats then, or is it going to be hassle?

The garage the MOT center sent me to did point to the Lambda and claimed it was "slow swiching".

Hence why I posted here for some advice. Want to get my facts straight and feel like I should not trust this MOT garage. Even if you get a free retest.

That's the problem then, if what I've read is right :)
 

NWhiteley

Active Member
You're not going to like the answer. Neither do I now though.

Kwik-Fit fitted it and now i'm seeing people complaining about them.

Is the Kwik-Fit centre, that did the cat, a MOT testing station? If not, find one that is, explain the problem, and they should do a before and after emmisions print out.
 

gamingboy

Well-known Member
I don't know how slow tbh! Just was told slow and they pointed out the misfire, which I know about. My mate noticed it as well.

Badger0-0 mate I do feel suspicous about them, but the whole garage thing is a minefield and when you need the car they've got you caught.

Don't know whether to take it for a twenty minute sprint and then see how the retest goes.
 

gamingboy

Well-known Member
Is the Kwik-Fit centre, that did the cat, a MOT testing station? If not, find one that is, explain the problem, and they should do a before and after emmisions print out.
I will find out tomorrow, can't remmber off of the top of my head. Need to find the receipt. I'm sure they have it on record though. So hoping that won't be a problem.

Sorry to sound such a numpty. If they try fobbing me off about the cat, do I just point out that everything else is fine on the paperwork.

Can't thank you guys enough!
 

NWhiteley

Active Member
You will probably need the reciept, and it will help if you take the VT30. Tell them you have had it checked and the Cat is at fault. You shouldnt have any problems getting it changed. Kwik-fit may not have the best of reputations, but they do honour their warranties.
 

gamingboy

Well-known Member
Cool, Thank you for that. :smashin:

I only got a VT30, VT32 and a yellow sheet detailing the emissions.

Will report back tomorrow.

Could I pick your brain again?

How long is the free MOT retest vaild for? Was told it's free, but on the paperwork says free within 10 days if left with garage, or if taken offsite then a partial fee may be charged.

Cheers again for help.
 

NWhiteley

Active Member
Cool, Thank you for that. :smashin:

I only got a VT30, VT32 and a yellow sheet detailing the emissions.

Will report back tomorrow.

Could I pick your brain again?

How long is the free MOT retest vaild for? Was told it's free, but on the paperwork says free within 10 days if left with garage, or if taken offsite then a partial fee may be charged.

Cheers again for help.
My bad, the VT40 is the check list we use when carrying out a MOT, its the VT30 you need. (i will edit my posts to correct this oversight)
It all depends on the garage, what it says on the paperwork is the minimum time you get. I would speak to the garage that MOTed the car, and explain that you are getting some work down under warranty, and see how long they will give you for the free re-test.
 

paulyoung666

Distinguished Member
the cat was changed and then the service was done , a misfire will allow unburnt fuel into the cat which will then knacker it quicktime :(
 

gamingboy

Well-known Member
Thank you everyone. All sorted.

Reset the ECU. Changed the leads. Passed.

Also getting the catalytic converter changed next week under warranty hopefully.
 

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