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Technical Barchetta emissions !!!

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Technical Barchetta emissions !!!

I feel for you, same problem every year with itv.

It drives me barmy that every day I follow some crappy old truck or bus straight out of the Flintstones kicking out more smog than a powerstation and somehow they have got a bloody itv sticker for this year, how do they get them through when little old barcky can't get through looking as clean as whistle?
 
Hi arnietwo and ratty99,
I am also at the limit of emissions since 3 years. I changed the first part of the exhaust and in a few weeks I will see if the problem is solved.
I investigated in the German Barchetta forum (barchetta-forum.de) and found that somebody solved it changing the catalysator. He already changed it for a "cheap" one and had to change it again for an original one.
Hope the tip helps to solve the emissions problem.
Good luck!
 
my two cents with labda sensors..

same problem.. new bosch sensor..

and problems all over the place.. erratic idle, emissions, check engine.

somehow am alfa/fiat specialist pointed out.. that i need to put an original sensor on.
a few pennies later .. for a original sensor magnetti marelli.. and all problems gone..
i didnt expected to fix the idle... but magically it did also.
 
Soon it will be my turn to go to yearly inspection. Last time I was out of allowed CO limits, but passed somehow, probably because inspection guys know and love my B :D

This time, having read last posts in this thread, I hooked my scanner to engine ECU and checked lambda related parameters.
It's strange. In the beginning, it shows "open loop" but still some lambda readings, sometimes well beyond 0.7V:

Lambda sensor status: Open loop (indicates whether the sensor is working (closed loop) or not (open loop)
Lambda sensor signal: 0.940V
Lambda sensor integration: 0.00% (ECU is not correcting based on lambda)

But after some warmup and moderate revs by me, it starts showing something like:

Lambda sensor status: Closed loop
Lambda sensor signal: 0.760V
Lambda sensor integration: -21.88% (ECU is making corrections)

These numbers change constantly and seem to be valid. But occasionally, it still falls back to open loop for some time, with 0% correction, and then again to closed loop with non-zero correction.
What exactly does "open/close loop" mean? is it about the power circuit used to warm the lambda sensor? it not, how come it is open loop but still showing some volts from the sensor?
Do I need a new lambda sensor? My car is 1996 with about 150kkm in its trunk, I don't think lambda has been replaced ever before.
 
wapper said:
Soon it will be my turn to go to yearly inspection. Last time I was out of allowed CO limits, but passed somehow, probably because inspection guys know and love my B :D

This time, having read last posts in this thread, I hooked my scanner to engine ECU and checked lambda related parameters.
It's strange. In the beginning, it shows "open loop" but still some lambda readings, sometimes well beyond 0.7V:

Lambda sensor status: Open loop (indicates whether the sensor is working (closed loop) or not (open loop)
Lambda sensor signal: 0.940V
Lambda sensor integration: 0.00% (ECU is not correcting based on lambda)

But after some warmup and moderate revs by me, it starts showing something like:

Lambda sensor status: Closed loop
Lambda sensor signal: 0.760V
Lambda sensor integration: -21.88% (ECU is making corrections)

These numbers change constantly and seem to be valid. But occasionally, it still falls back to open loop for some time, with 0% correction, and then again to closed loop with non-zero correction.
What exactly does "open/close loop" mean? is it about the power circuit used to warm the lambda sensor? it not, how come it is open loop but still showing some volts from the sensor?
Do I need a new lambda sensor? My car is 1996 with about 150kkm in its trunk, I don't think lambda has been replaced ever before.
Click to expand...
Open loop - ecu not using lambda sensor to adjust mixture.

Closed loop - ecu is using lambda sensor to adjust mixture.
 
Ok guys thanks for the replies. Went again for ITV today as i thought i had fixed an exhaust leak but failed again.
Readings this time
Idle 0.62
Revs 0.60
So i went to my friendly garage and he linked up his computer to the barchetta !! Ehhh to the ecu !!
And said that it wasnt responding ??
So he has tasked me with checking all fuses and to try and follow that computer plug all the way back to the fuse box or origin and see what i find.
Can you replace ur ECU ??
How difficult a job is that ??
 
I wouldn’t rush to change the ECU if the engine is running fine, more likely to be the diagnostics not working for some reason...I’d suggest trying somewhere else or doing it yourself ?
 
arnietwo said:
Can you replace ur ECU ??
How difficult a job is that ??
Click to expand...

Yes ECUs can be replaced BUT your replacement ECU has to be "virgin" / "factory new/reset". This is because the Fiat Code/Security system mates the ECU to the key code controller unit and to the key(s). Change any one of these then unless they are new/uncoded/virgin/factory reset units then the system will lock itself either at the ECU or the Key Code Controller.

Your high emissions could be due to any number of issues/problems so I would not be looking at replacing an ECU that appears to be working in all other respects.

I think you need to get an experienced technician/garage involved who can connect to the ECU, look at and test the real live data in conjunction with exhaust emissions etc. to then produce a conclusive diagnosis. All this work involve looking at a multitude of waveforms from the ECU *AND* being able to correctly read/interpret what is observed.
 
wapper said:
Soon it will be my turn to go to yearly inspection. Last time I was out of allowed CO limits, but passed somehow, probably because inspection guys know and love my B :D
...
Do I need a new lambda sensor? My car is 1996 with about 150kkm in its trunk, I don't think lambda has been replaced ever before.
Click to expand...

New lambda sensor installed (the cheapest available Denso DOX0119)
A tank full of fresh gasoline
15-20km on the highway before CO test

and my CO problem was solved, reading below 0.3% at 2000rpm (y)

The new sensor generally behaves the same way as old one, fluctuating between "open loop" and "close loop". The actual voltage values seem a little bit different, but not really sure.
 
Ok, so i have NOT looked at the car the past 6 weeks.
Sick of it !!!
Today checked all the fuses in the engine bay were ok, and checked AGAIN the exhaust connections.
Went to my garage and he said doesnt have the time to look over/ search for the problem ??
Did although say to look at Autodata and find out the numbers(ohms) of all the sensor connections, then i can put my meter on the plugs and see if all is ok ??
I went onto autodata but dint see where i get that info ?
Also think i am at the point of taking it to a Fiatg garage in the town south of me.
Im at breaking point, and i mean breaking point, if i get it through itv i might put it for sale ,!!!!
 
You can only check the resistance of the heater circuit, which should be around 4.5Ohm. But since you have new sensor, chances are heater is not the problem.
It is also strange that CO reading went worse with new sensor.

I would hook the scanner one more time and check lambda readings on revs and on idle, with cold and with hot engine.
Also worth checking if there is voltage coming from the ECU to heating pins of lambda connector.
 

Attachments

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Hello arnietwo,
At my ITV station they have to do several tries every year to get the allowed values. They said my lamda probe works fine. They told me there must be somewhere a leakage in the exhaust, although I changed the part with the flextube. I will have to take a closer look at the exhaust.
I would not trust very much on the Fiat dealer, they are used to connect the diagnosis machine and change the part not working fine. I would look for an old style mechanic.
In the attachment you can see the result of my ITV in the last 3 years (2019/2020/2021).
 

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  • ITV 2019 20 21.pdf
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Last edited:
What a nice CO figures you have there.
Too bad they are not realistic at all. For 20+ years old vehicles with Euro2 petrol engine, realistic would be 0.40-0.50% on idle and 0.25-0.30% on 2000rpm. Even if you have your car absolutely in order and with shiny new catalytic converter, the readings cannot be as low as they are in the PDF.
I guess these ITV guys do not take their work very seriously.
 
I find it hard to believe any CO readings under 0.1% vol. For petrol engines running on proper, stoichiometric mixture, with working catalytic converter.
And CO reading as low as zero is simply too good to be true : )
 
Thanx guys, wrapper those values are exactly the limits here, 0.5 at idle and 0.3 at 2000rpm.
I went today to another garage who has a barchetta in the garage window, but its never moved in the 10 years ive been here !
He said i need to weld that last exhaust joint, he said should replace fuel pressure regulator and spark plugs. When ive done that to go back and he will check emissions.
If still not good then change lambda sensor for original type !
So im still not beat !!
 
Hi! I have a 1995 Barchetta with high emissions as well. Actually very high.
CO 5.0 (0.5)
CO rev 2500 0,7 (0,3)
HC 337 (200)
Lambda 1,03 (0,9 - 1,03)
It is fitted with a new Lambda and new Catalysator

I notised the other day that there is an puddle of oil in the intake manifold. its hard to estimate the amount but it covers the entire bottom of the intake manifold when you look through the air intake.

Any ideas how it got there?
 
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