emissions way up

[bouncer]

Hello,
A friend of mine has a C200 w202 2.0 1995, a very tidy looking car. . . . but it is having emissions problems. He has been told to scrap it and buy a propper car. THIS IS A PROPER CAR!!!!!
I need some help to cure his issues.
The CO level is at 4.2 when is should be 0.3
The cat in new fitted in late december
The lambda sensor is new
There are no air leaks at the manifold or any of the vacume pipes.
where else do i look?

sTeVe

 

[recycled]

cane it up and down the mmotorway for 1hr to get it nice and hot.

 

[bouncer]

cane it up and down the mmotorway for 1hr to get it nice and hot.

Thats been done .
Mercedes stealer took £95 off him just to say it was the cat.
CO at 4.2 is pointing at an engine management issue, a cat can reduce emissions . . . . not increase them.
Evap purge????????


sTeVe

 

[stevesey]

However 4.2 is even above the 3.5 limit for '85->'92 pre cat cars, and everything else being OK I'd expect the a reading below that limit even if the Cat had gone.

You mention purge value - unplug and block of the manifold pipe, see what happens (assuming you have a method of measuring CO?). Hard to see how a few fumes would make that much difference though.

P.S. Double check the lamda sensor - that would have been my first point of call.

 

[Dieselman]

Those emissions are way too high even for a car with no cat fitted. The upstream Co should be about 1%.
He needs to sort this before it poisens the new cat, which I suspect it didn't need anyway.

The Lambda sensor should be controlling this and obviously isn't so that says the ECU isn't operating in closed loop function. Possibly the ECU is in limp home mode due to another fault.

Start with the basics ensure there are no vacuum leaks including the EGR an dpurge valves then check the temperature sensor.

It could be running on a cold temp setting.

The manual should have all the relevent sensor readings, if not take it into a fuel injection specialist.

 

[recycled]

are these the ones with no MAF?
they do suffer unregulated emissions too.
what about the lambda and the HC readings?

 

[Dieselman]

You mention purge value - unplug and block of the manifold pipe, see what happens (assuming you have a method of measuring CO?). Hard to see how a few fumes would make that much difference though.

You could use the Lambda reading. Should be 0.45 volt or measure with a AFR meter.
At this level just smelling it would be enough.

http://www.egauges.com/eg_typeI.asp...l&Letter=All&Needle=All&Diameter=All&Manf=All

I wonder what the reading is at higher revs than idle.?

 

[bouncer]

Thanks guys.
its had 2 lambda sensors latest one is from merc.
Temp sensor checked.
No vacuum leaks
Yes this is the one with NO MAF ( getting the rest of the emissions readings later today)

Where is the EGR on this engine ?

Thanks

sTeVe

 

[Dieselman]

Where is the EGR on this engine ?

Thanks

sTeVe

Good question, is there one.?

just looked on detaili site and that shows the system with a MAF. How does this engine know how much air is being injecsted?

 

[panason1c]

I assume the air filter has been checked/renewed?

 

[recycled]

it does not know how much air.
it is a case of manual fine tuning i think.

 

[Dieselman]

it does not know how much air.
it is a case of manual fine tuning i think.

There must be some way of detecting the amount of air, it runs closed loop.

If not then there must be an adjustment for the mixture.

Bouncer can you put the VIN into the detaili site and see what system comes up?

 

[bouncer]

I will get the Vin and any extra info as soon as i can
Thanks for the help guys.

sTeVe

 

[bouncer]

I have the VIN, My friend is looking for the emissions results. . . cant find them

VIN WDB20202F229161

Where do i put it? i have never had to use Detaili


sTeVe

 

[Dieselman]

here, but you're two didgits missing I think.

http://www.detali.ru/cat/oem_mb.asp


Think I've got it though..

does this look right..?
http://www.detali.ru/cat/OEM_MB0.asp?WDB=WDB2020202F229161

 

[bouncer]

here, but you're two didgits missing I think.

http://www.detali.ru/cat/oem_mb.asp


Think I've got it though..

does this look right..?
http://www.detali.ru/cat/OEM_MB0.asp?WDB=WDB2020202F229161

Yes thats it. . . . managed to miss a 20 off

sTeVe

 

[Dieselman]

It shows it with a MAF sensor.

 

[recycled]

how can you tell about the sensor? dieselman
Bouncer just look in the engine and see if it has got one o not. all these may be sorted by just changing it.
it is between the air filter box and the pipe across the engine cover

http://old.mbclub.ru/mb/vin/view.html

 

[Dieselman]

how can you tell about the sensor? dieselman

I mean the parts diagram shows a MAF sensor, for both setups shown for that engine type.

 

[bouncer]

I mean the parts diagram shows a MAF sensor, for both setups shown for that engine type.

Yes it does. . . My friend must be blind

Will get him to check again.

Thanks again guys

sTeVe