General MOT Failure - Emissions

[nexusmick]

My Grande Punto 2007 has recently failed. I am being told that I need to replace my top O2 sensor & my catalytic convertor.

Here is the emissions report:

Engine temp: = 95c - Pass

Fast Idle: - Fail

Engine speed: = 2510 rpm - Pass min - 2050 / max - 2750
CO: = 0.35% vol - Fail min - / max - 0.20
HC: = 133 ppm - Pass min - / max - 200
Lamda = 1.024 - Pass min - 0.970 / max - 1.030​

Second Fast Idle: - Fail

Engine speed: = 2390 rpm - Pass min - 2050 / max - 2750
CO: = 0.37% vol - Fail min - / max - 0.20
HC: = 129 ppm - Pass min - / max - 200
Lamda = 1.022 - Pass min - 0.970 / max - 1.030​

Natural Idle: - Pass

Engine speed: = 2390 rpm - Pass min - 2050 / max - 2750
CO: = 0.37% vol - Pass min - / max - 0.20

I am not sure if I need a cat as I had neglected the servicing of my car for the past year due to financial restraints.

Since this failed MOT I have replaced the top O2 sensor, oil & filter, air filter, spark plugs, leads and cleaned all the breather hoses, and run fuel treatment through the tank.

My questions are:

1. the recorded emissions from my car, how far out are they - By a lot / not a lot ?
2. Do you think my cat has given up the ghost ?
3. Shall I re-present for MOT on off chance the cat is fine ?

Any help would be appreciated as she is a great little car and I need to get her through the MOT !

Thank you for any & all replies..​

 

[varesecrazy]

Has it seen much use.. got thoroughly hot?

The natural idle figures..are they correct.?

 

[nikrox]

you could use Catclean,or similar..BUT as its failed you dont have the opportunity to drive the car round..

 

[DGPunto]

Your CO is high but not off the scale, old cars used to have limits up to 4.5%!

1. First thing I'd do is to give it a good service. When did you last change the oil, plugs and filters?

2. Have you checked the vent pipes that cross the top of the engine? They rot and upset the emissions

3. Get hold of a copy of MES (Link) and the cable they recommend. Then (assuming you have a laptop) you can do your own tests to see whether you're making things OK and to see if you have any fault codes

4. As above - if you can take it for a good run to clean the engine (you don't say if it's still taxed and insured but you obviously need those despite your MOT fail)

 

[varesecrazy]

Your CO is high but not off the scale, old cars used to have limits up to 4.5%!

1. First thing I'd do is to give it a good service. When did you last change the oil, plugs and filters?

2. Have you checked the vent pipes that cross the top of the engine? They rot and upset the emissions

3. Get hold of a copy of MES (Link) and the cable they recommend. Then (assuming you have a laptop) you can do your own tests to see whether you're making things OK and to see if you have any fault codes

4. As above - if you can take it for a good run to clean the engine (you don't say if it's still taxed and insured but you obviously need those despite your MOT fail)

They mentiond 50% of that..

I agree its not terrible..

Did that idle reading they stated look correct?

 

[torniojaws]

Had the same thing happen to my 2008 1.2 petrol last year. While you might change the air filter, spark plugs, oil and filter anyway as a good practice, it's not going to fix the emissions. At least in my case, the emissions were actually a bit higher(!) after that. Maybe a measurement error, but anyway...

The real fix is to get your fuel down to 1/4 full, and then add 10 liters of E85 ethanol fuel to the tank. Drive it around for about 30 mins at 3000+ rpm most of the time. Then head to the inspection directly after that. And immediately fill the tank up with normal 95 fuel, as it is not designed for ethanol fuel.

In my case, it passed with zero (literally) CO emissions The inspector was shocked...

After the inspection passed, I also did the catalytic converter wash that for example Scotty Kilmer has a video on. So basically fully sink your cat in water with about half a regular glass of liquid washing detergent overnight. Then wash it with water until no dirty water comes out anymore, and then let it dry fully. Then install it to the car again, making sure it is completely dry. Running it when it has water might crack it with the temperature it gets to in normal use (500 celsius or so).

The O2 sensors aren't that expensive and they are quite easy to replace on your own. You just need a special 22 mm socket with a slit on it to remove them, as they have a wire that goes from it to a power source. Something like this:

 

[nexusmick]

Has it seen much use.. got thoroughly hot?

The natural idle figures..are they correct.?

Unfortunately I don't think it was hot as my appointment was for 11am and as I had left it with them for 9am I suspect it was stone cold...

 

[nexusmick]

you could use Catclean,or similar..BUT as its failed you dont have the opportunity to drive the car round..

I have added some redex to a full tank at the required level but not sure if this will make a difference ? Mixed reports on additives so not sure what to believe...

 

[nexusmick]

Your CO is high but not off the scale, old cars used to have limits up to 4.5%!

1. First thing I'd do is to give it a good service. When did you last change the oil, plugs and filters?

2. Have you checked the vent pipes that cross the top of the engine? They rot and upset the emissions

3. Get hold of a copy of MES (Link) and the cable they recommend. Then (assuming you have a laptop) you can do your own tests to see whether you're making things OK and to see if you have any fault codes

4. As above - if you can take it for a good run to clean the engine (you don't say if it's still taxed and insured but you obviously need those despite your MOT fail)

I have changed top o2 sensor, plugs, leads, filters, oil change and cleaned/checked the vents pipes from airbox, manifold etc. since the MOT fail and a PO300 code I was getting has now cleared & not returned. It is rebooked for MOT today so will be giving it a good run beforehand to make sure it is nice & hot....

 

[nexusmick]

Had the same thing happen to my 2008 1.2 petrol last year. While you might change the air filter, spark plugs, oil and filter anyway as a good practice, it's not going to fix the emissions. At least in my case, the emissions were actually a bit higher(!) after that. Maybe a measurement error, but anyway...

The real fix is to get your fuel down to 1/4 full, and then add 10 liters of E85 ethanol fuel to the tank. Drive it around for about 30 mins at 3000+ rpm most of the time. Then head to the inspection directly after that. And immediately fill the tank up with normal 95 fuel, as it is not designed for ethanol fuel.

In my case, it passed with zero (literally) CO emissions The inspector was shocked...

After the inspection passed, I also did the catalytic converter wash that for example Scotty Kilmer has a video on. So basically fully sink your cat in water with about half a regular glass of liquid washing detergent overnight. Then wash it with water until no dirty water comes out anymore, and then let it dry fully. Then install it to the car again, making sure it is completely dry. Running it when it has water might crack it with the temperature it gets to in normal use (500 celsius or so).

The O2 sensors aren't that expensive and they are quite easy to replace on your own. You just need a special 22 mm socket with a slit on it to remove them, as they have a wire that goes from it to a power source. Something like this:

I have also replaced the top O2 sensor also as well as plugs, leads, air, oil filter as well as an oil change. She is booked in for another MOT today so am going to run her up so she is hot and will cross my fingers in the hope that she may pass ?

 

[nexusmick]

Has it seen much use.. got thoroughly hot?

The natural idle figures..are they correct.?

She is normally only used on short journeys daily but around 10-15 miles a day urban driving. I presume they are the correct natural idle figures ?

 

[nexusmick]

you could use Catclean,or similar..BUT as its failed you dont have the opportunity to drive the car round..

Does cataclean really work ? I have read mixed reviews on some of these additives so am unsure as to what to believe. I have put some redex into the tank but again am not sure if this stuff really works ?

 

[nikrox]

Its 'supposed' to be a quality product. And its guaranteed..to be fair my friends GP only does short runs too ,probs a majority of runs 2 miles each way daily.
That car struggled with emissions too.
An old favourite is to wrag the car in 3rd for 10 miles or so to clean the cat out,before the mot.
Trouble being they don't get hot enough on short run's.

 

[nexusmick]

Well, second MOT and failed again so I suppose I will have to bite the bullet and purchase a new catalytic converter.

So do I need gaskets to replace the manicat ?

 

[torniojaws]

Well, second MOT and failed again so I suppose I will have to bite the bullet and purchase a new catalytic converter.

So do I need gaskets to replace the manicat ?

Yes, you need two of them, but they are cheap:

- Part nr 55197682 for the exhaust manifold
- Part nr 51814153 for the middle exhaust pipe

When I removed my cat for cleaning, two of the exhaust manifold studs snapped clean, so be careful with them. You might also replace them with new ones for about 1 EUR / 0,85 GBP / 1,1 USD per piece - part nr 46470396. You'll need 8 of them, unless they have been replaced recently.

 

[nexusmick]

Yes, you need two of them:

- Part nr 55197682 for the exhaust manifold
- Part nr 51814153 for the middle exhaust pipe

When I removed my cat for cleaning, two of the exhaust manifold studs snapped clean, so be careful with them. You might also replace them with new ones (about 1 EUR / 0,85 GBP / 1,1 USD per piece - you'll need 8 of them), unless they have been replaced recently.

Thank you for those part numbers and for your advice regarding the studs. I have now replaced the cat with said gaskets and all looks good so far and no snapped studs, so all I need do now is re-submit for MOT and see if my old girl passes, fingers crossed. Will update when the outcome is known... Here's hoping for a good result....! So all I need do now is change the gearbox oil, bleed the clutch & brakes, replace some worn springs, front & rear, top mounts and change a rear tyre as it is getting low on the tread and all will be well.... Roll on the good weather that is yet to come.... Or maybe I should be looking at replacing the old girl.... 104,000 miles.... I can't do it, she has been serving me well.....!

 

[Rado77]

Or maybe I should be looking at replacing the old girl.... 104,000 miles....

That's the right way ;-)

 

[nexusmick]

That's the right way ;-)

I can't quite bring myself to doing it just yet, she is giving me so much joy still & she is great to be tinkering with......

 

[Rado77]

I thought like that because you mentioned all those things which are planned to change

 

[torniojaws]

the gearbox oil

Easier than changing the engine oil Hex 12 + Hex 8, and 1,5 liters of gearbox fluid. Plus a funnel with a long hose that can fit from top of the engine to the filler plug. On mine (left side wheel) it is between the coolant reservoir and the air filter box, near the lower part of the engine. The drain is close to the left front tire control arm, pointing toward the rear in about a 45 degree "angle" (sort of).

bleed the clutch & brakes

Straightforward, but takes a bit of time. On mine, there was an odd mix of 7mm and 8mm valves. I think the rear brakes had 7 mm inside a small "valley" that you can only reach with a 7 mm socket. Couldn't get to it with a wrench.

replace some worn springs, front & rear, top mounts

The front was quite straightforward, but lots of things to do. The hex bit in the top of the strut mount will probably give you trouble/strip, if the strut is old. You might need to grab the strut pipe with vice grips, even though it is not recommended. Could try putting some piece of rubber/leather between the steel and the grips.

I haven't done the rears on mine, but I think it is basically about loosening the bottom strut bolt, twisting the control arm downwards and pulling the spring out at the same time. Then push the new one in.