2000 ML320 Failed Emissions

[Justin]

My brother has a 2000 ML320. It is in for Pennsylvania inspection, and
for whatever reason the emissions diagnostic test failed.
The mechanic said he has to drive it for a while so something can reset,
or eventually pass.

Is this true? Is there a fix?

[Cordy]

Post by Justin
My brother has a 2000 ML320. It is in for Pennsylvania inspection, and
for whatever reason the emissions diagnostic test failed. The mechanic
said he has to drive it for a while so something can reset, or
eventually pass.
Is this true? Is there a fix?

Sure. The suggestion is correct: drive it for a while, possibly on
highway, at high rotation speed of the engine. The "filter" of the exaust
system needs cleaning, probably, but the electronics only allow the
process while using the engine at high speed and high power.
It's quite common here in Europe. No extra action is usually required.

[t***@optonline.net]

My brother has a 2000 ML320.  It is in for Pennsylvania inspection, and
for whatever reason the emissions diagnostic test failed. The mechanic
said he has to drive it for a while so something can reset, or
eventually pass.
Is this true?  Is there a fix?

Sure. The suggestion is correct: drive it for a while, possibly on  
highway, at high rotation speed of the engine. The "filter" of the exaust
system needs cleaning, probably, but the electronics only allow the
process while using the engine at high speed and high power.
It's quite common here in Europe. No extra action is usually required.
--
Ciao!
Stefano

Assuming the car has been driven normally, then
no, there should be no need to drive it more to get
the emissions correct. The whole point of emissions
controls is for them to be working all the time in
any kind of driving.

Was any work done on the car, eg replace an emission
sensor? If that's the case, then having to drive it makes
sense. The onboard computer logs certain emission
systems parameters and if they are working correctly,
it sets flags saying they are OK. It takes some period
of driving for all of those flags to get set. And when you
take it for inspection here in the USA, they hook eqpt on
to the car computer that reads those flags and they
must be set to pass. Actually, here in NJ with a late
model car you can have one flag that is not set and
still pass. Not being set does not mean there is a
problem, it just means the computer has not logged
enough data to validate that particular emission
system is working.

So, let's say you brought a car in and it failed because
the computer was reporting a problem in the fuel evap
system. The mechanic found a leaking gas cap and
replaced it. He can then clear that trouble code, but
the emission monitor will not set the OK flag you need
to pass inspection until it sees enough data that the
system is working OK. That requires just using the
car in normal driving. Most of those monitors get set
within minutes, but some, like the fuel evap system,
require days. It's also not clear exactly what sets that
one, ie if it's hours of engine operation, miles driven,
start/shut off cycles, or some combination.

So, bottom line, if work was done to fix a problem, then
what he was told makes sense. If not, then it makes
no sense to me.

[Cordy]

Post by Cordy

My brother has a 2000 ML320.  It is in for Pennsylvania inspection,
and for whatever reason the emissions diagnostic test failed. The
mechanic said he has to drive it for a while so something can reset,
or eventually pass.
Is this true?  Is there a fix?

Sure. The suggestion is correct: drive it for a while, possibly on
highway, at high rotation speed of the engine. The "filter" of the
exaust system needs cleaning, probably, but the electronics only allow
the process while using the engine at high speed and high power. It's
quite common here in Europe. No extra action is usually required.
--
Ciao!
Stefano

Assuming the car has been driven normally, then no, there should be no
need to drive it more to get the emissions correct. The whole point of
emissions controls is for them to be working all the time in any kind of
driving.
Was any work done on the car, eg replace an emission sensor? If that's
the case, then having to drive it makes sense. The onboard computer
logs certain emission systems parameters and if they are working
correctly, it sets flags saying they are OK. It takes some period of
driving for all of those flags to get set. And when you take it for
inspection here in the USA, they hook eqpt on to the car computer that
reads those flags and they must be set to pass. Actually, here in NJ
with a late model car you can have one flag that is not set and still
pass. Not being set does not mean there is a problem, it just means the
computer has not logged enough data to validate that particular emission
system is working.
So, let's say you brought a car in and it failed because the computer
was reporting a problem in the fuel evap system. The mechanic found a
leaking gas cap and replaced it. He can then clear that trouble code,
but the emission monitor will not set the OK flag you need to pass
inspection until it sees enough data that the system is working OK.
That requires just using the car in normal driving. Most of those
monitors get set within minutes, but some, like the fuel evap system,
require days. It's also not clear exactly what sets that one, ie if
it's hours of engine operation, miles driven, start/shut off cycles, or
some combination.
So, bottom line, if work was done to fix a problem, then what he was
told makes sense. If not, then it makes no sense to me.

WE're talking about a 2000 car. I mean, a year 2000. I remember that for
older cars (and anti-pollution equipment and regulations) the electronic
system is a little bit less... evolved (complicated? :) ).
So, I presumed it didn't run thoroughly the anti-clogging (diesel) or
catalytic regeneration (gasoline) cycle.
That's where my statement that the suggestion to "drive it on a highway"
makes sense. Interesting information, in your post, however.

You might know that here in Europe we have several different levels of
emissions measured, according to numbered standards. Euro1-2-3... we
actually are on 5, waiting for level 6 to be disclosed. This in fact is a
"commercial" numbering system: the actual standard have some over-
complicated numbering systems...
For example:
http://www.hymerclubitalia.it/euro.html

The page could be titled, in english: which euro corresponds to my
vehicle? Especially interesting the last table... ;)

[t***@optonline.net]

Post by Cordy

Post by Cordy

My brother has a 2000 ML320.  It is in for Pennsylvania inspection,
and for whatever reason the emissions diagnostic test failed. The
mechanic said he has to drive it for a while so something can reset,
or eventually pass.
Is this true?  Is there a fix?

Sure. The suggestion is correct: drive it for a while, possibly on
highway, at high rotation speed of the engine. The "filter" of the
exaust system needs cleaning, probably, but the electronics only allow
the process while using the engine at high speed and high power. It's
quite common here in Europe. No extra action is usually required.
--
Ciao!
Stefano

Assuming the car has been driven normally, then no, there should be no
need to drive it more to get the emissions correct.  The whole point of
emissions controls is for them to be working all the time in any kind of
driving.
Was any work done on the car, eg replace an emission sensor?  If that's
the case, then having to drive it makes sense.  The onboard computer
logs certain emission systems parameters and if they are working
correctly, it sets flags saying they are OK.   It takes some period of
driving for all of those flags to get set.  And when you take it for
inspection here in the USA, they hook eqpt on to the car computer that
reads those flags and they must be set to pass.  Actually, here in NJ
with a late model car you can have one flag that is not set and still
pass.  Not being set does not mean there is a problem, it just means the
computer has not logged enough data to validate that particular emission
system is working.
So, let's say you brought a car in and it failed because the computer
was reporting a problem in the fuel evap system.  The mechanic found a
leaking gas cap and replaced it.   He can then clear that trouble code,
but the emission monitor will not set the OK flag you need to pass
inspection until it sees enough data that the system is working OK.
That requires just using the car in normal driving.  Most of those
monitors get set within minutes, but some, like the fuel evap system,
require days.  It's also not clear exactly what sets that one, ie if
it's hours of engine operation, miles driven, start/shut off cycles, or> > some combination.
So, bottom line, if work was done to fix a problem, then what he was
told makes sense.  If not, then it makes no sense to me.

WE're talking about a 2000 car. I mean, a year 2000. I remember that for
older cars (and anti-pollution equipment and regulations) the electronic
system is a little bit less... evolved (complicated? :) ).

/
The same basic emission monitors are part of OBDII that
went into effect in 1996.

Post by Cordy
So, I presumed it didn't run thoroughly the anti-clogging (diesel) or
catalytic regeneration (gasoline) cycle.
That's where my statement that the suggestion to "drive it on a highway"
makes sense.

I don't know of any mechanic here in the USA that when
presented with a car that had been in routine use that
has failed emissions would tell them to drive it on
a highway as a solution. For example, the catalytic
converter should function and meet emissions standards
whether driven in the city or on a highway.



Interesting information, in your post, however.

Post by Cordy
You might know that here in Europe we have several different levels of
emissions measured, according to numbered standards. Euro1-2-3... we
actually are on 5, waiting for level 6 to be disclosed. This in fact is a
"commercial" numbering system: the actual standard have some over-
complicated numbering systems...

Here in the USA many states don;t measure emissions at
inspection directly. They just use the information from the
cars computer that shows the systems are working.

Post by Cordy
For example:http://www.hymerclubitalia.it/euro.html
The page could be titled, in english: which euro corresponds to my
vehicle? Especially interesting the last table... ;)
--
Ciao!
Stefano- Hide quoted text -
- Show quoted text -

[Cordy]

Il Thu, 06 Oct 2011 14:07:08 -0700, ***@optonline.net ha scritto:
---------
Here in the USA many states don't measure emissions at
inspection directly. They just use the information from the
cars computer that shows the systems are working.
---------

Well, here in Italy we only measure the final result (i.e. emissions are
controlled, no electronic is connected to the car).

And for euro 2 it might happen that you are being checked in a "not
favorable" moment (if I can express myself in this way).
Since you are asked to maintain the car with emission levels comparable
to those declared when it was coming out of the factory (and not
better...), you only need to drive it for a while, to obtain a (possibly,
if nothing is really wrong) correct emission level.
As a matter of fact, Euro 2 standard only measures emissions with engine
in "standard working conditions" (the original standard was based on
levels measured in controlled conditions, with tests run in engine test
room).

I own a euro2 VW (Polo, gasoline, converted to LPG) of the same age of the
ML320 of the OP and this happened to me at the time of the second check
(2005). Simply driving it 5 km on the high speed ring around the town was
enough to obtain a substantial reduction of emissions. After LPG
conversion, I know I need to drive for a few kilometers using gasoline,
in order to obtain a correct measurement: it's a sort of "reactivation"
of the catalyzator. If I just drive to the test station running LPG and
switch to gasoline there, for testing, the result is that the catalysator
is running poorly and emissions are too high. It's a fact, but don't ask
me why... :)

Of course, this doesn't mean anything at all, for the USA! :)
It's just for... well, general information? :D

[t***@optonline.net]

Post by Cordy
---------
Here in the USA many states don't measure emissions at
inspection directly.  They just use the information from the
cars computer that shows the systems are working.
---------
Well, here in Italy we only measure the final result (i.e. emissions are
controlled, no electronic is connected to the car).
And for euro 2 it might happen that you are being checked in a "not
favorable" moment (if I can express myself in this way).
Since you are asked to maintain the car with emission levels comparable
to those declared when it was coming out of the factory (and not
better...), you only need to drive it for a while, to obtain a (possibly,
if nothing is really wrong) correct emission level.
As a matter of fact, Euro 2 standard only measures emissions with engine
in "standard working conditions" (the original standard was based on
levels measured in controlled conditions, with tests run in engine test
room).
I own a euro2 VW (Polo, gasoline, converted to LPG) of the same age of the
ML320 of the OP and this happened to me at the time of the second check
(2005). Simply driving it 5 km on the high speed ring around the town was
enough to obtain a substantial reduction of emissions. After LPG
conversion, I know I need to drive for a few kilometers using gasoline,
in order to obtain a correct measurement: it's a sort of "reactivation"
of the catalyzator. If I just drive to the test station running LPG and
switch to gasoline there, for testing, the result is that the catalysator
is running poorly and emissions are too high. It's a fact, but don't ask
me why... :)
Of course, this doesn't mean anything at all, for the USA! :)
It's just for... well, general information? :D
--
Ciao!
Stefano

Interesting and I see your point. Here in NJ they used to
check the actual emissions too. First, in the 80s, it was
just a check with the car idling. Then in the 90s, the
federal EPA
ordered states here in the northeast to do more stringent
testing that included running the car at highway speeds
on a dynamometer while measuring the tailpipe emissions.
Christie Whitman was governor at the time. Instead of
fighting this nonsense, she lamely went ahead with it.
It cost $500mil+ to outfit all the state inspection stations
with the dynamometer and new eqpt. There were cost
overruns, screw up one after the other, nothing done on
time, hours long lines at inspection, etc. That system was used for
about 4 years, after which the EPA ok's using the OBDII computer data
from
the car instead. In other words, they scrapped all that
$500mil eqpt and just hook up a cable to the OBDII
connector under the dash.

That shows you the malfeasance and incompetence at
the EPA. Surely they were already working with the car
manufacturers to use OBDII at the very time they insisted
that all that money be spent on a system that would be
gone in a few short years.

I don't know how Pennsylvania, the state in question,
does emission testing.

[Cordy]

Post by t***@optonline.net
federal EPA
ordered states here in the northeast to do more stringent testing that
included running the car at highway speeds on a dynamometer while
measuring the tailpipe emissions.

That's what we do, now. But the dynamometer is being used to test brakes.
Which seems to be correct, imho. Together with a phonemeter to test horns
and a light measuring system for headlights. Operator eyes to test all
the other lights... :)

Post by t***@optonline.net
It cost $500mil+ to outfit all the state inspection stations with the
dynamometer and new eqpt. There were cost overruns, screw up one after
the other, nothing done on time, hours long lines at inspection, etc.
That system was used for about 4 years, after which the EPA ok's using
the OBDII computer data from
the car instead. In other words, they scrapped all that $500mil eqpt
and just hook up a cable to the OBDII connector under the dash.

Do you know the proverb? Bad thinking is sin, but usually true: briberies?

Post by t***@optonline.net
That shows you the malfeasance and incompetence at the EPA. Surely they
were already working with the car manufacturers to use OBDII at the very
time they insisted that all that money be spent on a system that would
be gone in a few short years.
I don't know how Pennsylvania, the state in question, does emission
testing.

[t***@optonline.net]

Post by Cordy

 federal EPA
ordered states here in the northeast to do more stringent testing that
included running the car at highway speeds on a dynamometer while
measuring the tailpipe emissions.

That's what we do, now. But the dynamometer is being used to test brakes.
Which seems to be correct, imho. Together with a phonemeter to test horns
and a light measuring system for headlights. Operator eyes to test all
the other lights... :)

That brings up another interesting inspection thing
here in NJ. They used to test many things:

brakes
headlight aiming
windshield wipers
horn
emissions at idle
front suspension, eg ball joints (they actually lifted
the car and the guy would try to rock the wheel
by hand)

Then in addition to that, in the 90s they added the dynamometer thing
to test emissions at highway speed.

Then starting around 2000 they got rid of just
about all of the above. I'm actually not sure
if they test anything other than brakes and
emissions, the latter being done by connecting
to the OBDII on the car. They might check
lights for working, but the aiming part is long
gone. So is the front end check and I don't
remember hearing any horns blowing either.
Next time I'm there I'll pay closer attention.

Oh and new cars no longer need to be inspected
for 5 years. No more inspections on motorcycles.
Oh my, maybe we're all gonna die!

[Cordy]

Oh and new cars no longer need to be inspected for 5 years. No more
inspections on motorcycles. Oh my, maybe we're all gonna die!

:D I don't know how we could drive such uncontrolled cars, in the '70s and
'80s... I'm a survivor!!! :D

[t***@optonline.net]

Post by Cordy

Oh and new cars no longer need to be inspected for 5 years.  No more
inspections on motorcycles. Oh my, maybe we're all gonna die!

:D I don't know how we could drive such uncontrolled cars, in the '70s and
'80s... I'm a survivor!!! :D
--
Ciao!
Stefano

I forgot the best part. In addition to motorcycles, diesel cars
older than 1994 or 96 no longer need to be inspected here in
N J at all. I won't have to take the 80 300SD for inspection
ever again!

[Tiger]

It is 1996 or older diesel cars in NJ doesn't need inspection... just peel
of those inspection stickers... whoohoo!

[Tiger]

Pennsylvania inspection is done by private garage that pretty much only does
inspection.... or was it PA facility... It has been a long while when I did
it. They had a RPM meter that they wanted you to raise the engine RPM to
2000 while they take emission reading. Other stuff is safety light... and
that was it. It was not as comprehensive as NJ.

[t***@optonline.net]

Post by Tiger
Pennsylvania inspection is done by private garage that pretty much only does
inspection.... or was it PA facility... It has been a long while when I did
it. They had a RPM meter that they wanted you to raise the engine RPM to
2000 while they take emission reading. Other stuff is safety light... and
that was it. It was not as comprehensive as NJ.

As I pointed out earlier, I don't think there is much safety
related in the inspection here in NJ anymore either. They
used to check brakes, front end joints, wipers, horn, lights,
headlight aiming, glass for cracks, etc. Now for sure the
front end joints and headlight aiming are gone. I'm pretty sure
even the lights working are done too. When you drove up
they used to ask you to turn on hi beams, low beams, left
turn signal, etc., one at a time, I know they don't do that anymore,
but it's
possible they are doing it when the inspector moves the
car through the line. Next time I'll watch more closely,
when I take my other car in.
But I know I have not heard horns blowing anymore either,
so I suspect all that is gone. You used to have to get
even new cars inspected every year. Now new ones
are good I think for 5 and others every 2.

Only things I know they do for sure is emissions via the
car computer and brake test where they hit them while
rolling across a test pad at about 5mph that shows the
force on each wheel.

[Stephen Gluck]

Don't know if this is true on a Mercedes but, if a trouble code was
recently cleared by an OBDII reader, the car has to driven both
highway and street fo rabout 50 miles for the sensors to reset. Had it
happen to my Ford Explorer recently. My E350 4Matic is too new for a
problem like this to occur. (I hope)
On Tue, 04 Oct 2011 17:27:14 -0400, Justin

Post by Justin
My brother has a 2000 ML320. It is in for Pennsylvania inspection, and
for whatever reason the emissions diagnostic test failed.
The mechanic said he has to drive it for a while so something can reset,
or eventually pass.
Is this true? Is there a fix?

[t***@optonline.net]

Post by Stephen Gluck
Don't know if this is true on a Mercedes but, if a trouble code was
recently cleared  by an OBDII reader, the car has to driven both
highway and street fo rabout 50 miles for the sensors to reset. Had it
happen to my Ford Explorer recently. My E350 4Matic is too new for a
problem like this to occur. (I hope)
On Tue, 04 Oct 2011 17:27:14 -0400, Justin

It's actually the other way around. It takes a certain amount
of driving to SET the emissions monitors after they have
been cleared. Most of them set within 15 mins or so of
driving. The most notorious is the fuel evaporation system
which takes much longer to set. No one seems to know
exactly what it takes to get it set either, ie is it highway
driving, stop and go, either, engine run time, etc. Also,
I don't understand why it would take so long as my
understanding of what it's looking for is maintenance of
a certain pressure in the gas tank, which indicates that
there are no leaks to allow vapors out.

Here in NJ you can pass the state emissions test with a
recent vintage car with 1 not set. With an older car, I
think they may allow 2.