Back again. Good and bad news.

Good news first

I could run MES and check more parameters

Battery now at rest is at 13v, a bit higher after charging it, and same value with engine running and warm, 13,96v.

Throttle position reset as per Workshop instruction and it works perfectly. Being at 4,2º at rest, flowing in paralel as the pedal, and always go back to rest position

Bad news. Lambda values are quite low, close to 0,90%, so poor mix what causes high CO levels. It should closer to 1, being 1 the perfect value and between 0,995 and 1,005 the optimal. I've checked it as well without air filter, just to try provide more aire to the engine. It has improved, increased to 0,93%, but still far from 1. At least I know that lambda is not correcting as expecting. Now I have to determine if it is because of the sensor itself or because of any other reason.

I couldn't drive it, so all tests have been done warm but stopped.

Next, test the old lambda sensor and see if there is any change in the values. I couldn't today either


Two videos. Sorry for the Spanish, I realized late it wasn't in English:

Lambda correction with air filter
https://www.youtube.com/watch?v=8IINxTBdY4Y

Lambda correction without airfilter, but full box installed
https://www.youtube.com/watch?v=nCZXlNmSQMk

More tests done.

Old lambda installed after cleaning. Se the comparison, old cleaned is Bosch, new dirty is Maxgear

Now Lambda correction value reaches 1% when revving with air filter installed, which is good and much better than before, in theory. At least we know that lambda sensor is making a difference. However, gases from exhaust smell much more like petrol, this worries me a bit

https://www.youtube.com/watch?v=ahLGAJQ6Skw


Idle is fine, same as before. No noise of anything broken inside the cat. But discovered hte reason for the metallic noise I hear from time to time, an engine mount broken. I've found as well a leak of coolant in one of the coolant caps in the block

https://www.youtube.com/watch?v=CggnH405UeM


I'm thinking to apply the inyector cleaner and go to MOT now that Lambda is better, what do you think?

majobusa said:

More tests done.

Old lambda installed after cleaning. Se the comparison, old cleaned is Bosch, new dirty is Maxgear

Now Lambda correction value reaches 1% when revving with air filter installed, which is good and much better than before, in theory. At least we know that lambda sensor is making a difference. However, gases from exhaust smell much more like petrol, this worries me a bit

https://www.youtube.com/watch?v=ahLGAJQ6Skw


Idle is fine, same as before. No noise of anything broken inside the cat. But discovered hte reason for the metallic noise I hear from time to time, an engine mount broken. I've found as well a leak of coolant in one of the coolant caps in the block

https://www.youtube.com/watch?v=CggnH405UeM


I'm thinking to apply the inyector cleaner and go to MOT now that Lambda is better, what do you think?

Click to expand...

Yes do that but if still doesn't pass I really think time for new catalytic converter given age and mileage of you current cat.

The coolant leaking core plug will need replacing repair when mot passed.
Good luck
Jack

The lambda correction needs to be graphed really to see the switching of the o2 sensor, I'm not 100% sure but it looks like the lambda correction looks like the o2 sensor voltage on a different scale.

If that is the case at least you can see if o2 sensor signal switching.

Don't get rid of new sensor , are there any numbers on the new sensor?

jackwhoo said:

Yes do that but if still doesn't pass I really think time for new catalytic converter given age and mileage of you current cat.

The coolant leaking core plug will need replacing repair when mot passed.
Good luck
Jack

The lambda correction needs to be graphed really to see the switching of the o2 sensor, I'm not 100% sure but it looks like the lambda correction looks like the o2 sensor voltage on a different scale.

If that is the case at least you can see if o2 sensor signal switching.

Don't get rid of new sensor , are there any numbers on the new sensor?

Click to expand...

This afternoon I could tested it driving. And it feels awesome! The acceleration is soooo smooth, before it was rude, not linear. Now is so pleasant. Idle is perfect, it didn't hold at 2000 or any other revs, always going down to idle when shifthing gear. So idle issue finally solved!


Now the CO levels. After 30 kms driving I came home and check again the lambda,it is always so close to 1 if not 1, so perfect. I'm gonna try tomorrow early in the morning, to get as much as possible oxygen whit lower temperatures.
Video of the Lambda reading. voltage is not available for this car, I guess because the connection is just the 3 pin cable, so "OBD1".Or I couldn't find it...

https://www.youtube.com/watch?v=pAwiVzutXJc

The newer lambda removed has these numbers, which are the model and I would say the date when manufactured. And now looks like this after cleaning it as well

majobusa said:

This afternoon I could tested it driving. And it feels awesome! The acceleration is soooo smooth, before it was rude, not linear. Now is so pleasant. Idle is perfect, it didn't hold at 2000 or any other revs, always going down to idle when shifthing gear. So idle issue finally solved!


Now the CO levels. After 30 kms driving I came home and check again the lambda,it is always so close to 1 if not 1, so perfect. I'm gonna try tomorrow early in the morning, to get as much as possible oxygen whit lower temperatures.
Video of the Lambda reading. voltage is not available for this car, I guess because the connection is just the 3 pin cable, so "OBD1".Or I couldn't find it...

https://www.youtube.com/watch?v=pAwiVzutXJc

The newer lambda removed has these numbers, which are the model and I would say the date when manufactured. And now looks like this after cleaning it as well

Click to expand...

I am so happy it is looking better for you ((-:

Thanks for picture of numbers on maxgear sensor they look nothing like a ntk/ngk sensor so it could confirm a cheap poorly made sensor.

I wish you very good luck for your test tomorrow.

Best wishes

Jack

Thanks!!!! I cross my fingers as well. I'm so nervous, like when I was younger before the final exam at university I'll let you know the result asap.

Yeap, when comparing both visually and the weight the diference is big, that's the reason Bosch costs almost the double. Leason learned

No luck

CO idle is in the upper limit, 0,3%, but in. Lambda values the same, 1,012. CO rev still high, 0,61.

I came to my local Fiat dealer looking for advice. They don't have the machine to review the CO, but their diagnostic is the catalytic converter. Because car runs well, no error recorded, and cat is 25 years old and 355000 km.

My though is that all this time with high idle and bad combustion has killed the remaining good staff in the cat, if there was any...

By the way, this is the noise cat was so8ng when I arrived at home
https://youtu.be/gRG9jIkKiqE

Hi,
Definately time for a new catalytic converter .
The problem you have had with mot has resulted in you refitting the Bosch o2 sensor making you car much nicer to drive which is very positive.
I am very confident a new catalytic converter will get a mot pass.

When you get mot pass find a new exhaust manifold, the paste is a temporary repair and when the cracks are open again the engine will run with too much fuel and damage your new catalytic converter.

Good luck Keep us updated.

Best wishes

Jack

jackwhoo said:

Hi,
Definately time for a new catalytic converter .
The problem you have had with mot has resulted in you refitting the Bosch o2 sensor making you car much nicer to drive which is very positive.
I am very confident a new catalytic converter will get a mot pass.

When you get mot pass find a new exhaust manifold, the paste is a temporary repair and when the cracks are open again the engine will run with too much fuel and damage your new catalytic converter.

Good luck Keep us updated.

Best wishes

Jack

Click to expand...

Thanks for highlighting the postive side. In addition I have discovered IAWScan2 and learned a lot about MES and parameters. I have taken the decision to give him (yes, him) another chance. I'll buy that cheap cat I've located in internet, made by Bosal, and come back to the MOT.

If passes, the intention is to exchange the exhaust manifold and the coolant cap in the block at the same time.

I'll order it asap and will arrive in one week more less. Any advice about the new cat? Shall I drive some kms before going to the MOT? Will it work from minute one?

Thanks again Jack!

majobusa said:

Thanks for highlighting the postive side. In addition I have discovered IAWScan2 and learned a lot about MES and parameters. I have taken the decision to give him (yes, him) another chance. I'll buy that cheap cat I've located in internet, made by Bosal, and come back to the MOT.

If passes, the intention is to exchange the exhaust manifold and the coolant cap in the block at the same time.

I'll order it asap and will arrive in one week more less. Any advice about the new cat? Shall I drive some kms before going to the MOT? Will it work from minute one?

Thanks again Jack!

Click to expand...

Hi Majo,

Thank you so much, it is a pleasure to help you .you are a very kind polite person

It will be so much more of a pleasure for me if your car passes your mot test .

Catalytic converters work straight away but you would be sensible to drive gently for the first 30 to 50 kilometres.

Please post again.

Best wishes

Jack

Very nice words Jack. But it is easy be kind and polite when talking to a gentleman ;-)

Cat bought. Hopefully I'll receive it next Friday to install it during the weekend. If plans come together, on Monday I'll go to the MOT again.

Thanks for the recomendation, it is going to be my first time premiering a catalytic converter.

Keep you posted

Best regards

As expected, I received the new cat on Friday and installed it today, hopefully well done... Tomorrow I'll go to the MOT, let's see... but looks good because gases smell much better

Some pictures, they always help

And comparison interior old vs new

majobusa said:

And comparison interior old vs new

Click to expand...

Hello,
Thanks for update pictures.
New part looking good
Fingers crossed for you for tomorrow(-:

Old cat looks like it is breaking up .

Don't get rid of the old catalytic converter just yet.

Best wishes
Jack

You read my mind I kept the old cat at home just in case until I finally pass the MOT

Thanks for giving mood. I'll let you know asap

Cheers

Finally passed!!

And results (marks) can't be better. CO idle 0,0%, CO Rev 0,0%. One year more with him. Now I have time to change the exhaust manifold, rear exhaust (yesterday I noticed it is in a very bad condition internally), coolant leak, engine mount and if there is budget all shocks. Step by step...

Thank you really much Jack for all your help and support. It has been really useful, not only because of your good advices, but also for listening and paying attetion to my case.

I hope we keep in touch

Best regards

excellent news, good work

so browsing random parts sellers, as you do, come across new old stock manifolds at partsworld... if your still looking for one majobusa.

https://www.ebay.co.uk/itm/372847407088

blu73 said:

so browsing random parts sellers, as you do, come across new old stock manifolds at partsworld... if your still looking for one majobusa.

https://www.ebay.co.uk/itm/372847407088

Click to expand...

thanks for remembering me blu73!

Actually it is a really good price even including shipment. The cheaper I found was around 100€ (90£). Because of that I took one from scrapyard per 18€ (16£) last week. I've it in the carport awaiting for some free time to be installed. But definitively If I were found that one before I would take it brand new.

yeah i don't think i'd have even considered trying to find a new one if i was in your shoes, just spotted it and thought of you though.