NAC..'00 VW Passat 4Motion...$7200 in repairs!!!

[Matt Evans]

A few comments, inline 

> -----Original Message-----
> From: quattro-bounces at audifans.com 
> Subject: Re: NAC..'00 VW Passat 4Motion...$7200 in repairs!!!

> On Jun 10, 2005, at 3:58 PM, Tyson Varosyan wrote:
> 
> > Do what many people I know do on all their cars. Take a 
> hole saw with 
> > a long extension, take out your cat, and drill the thing 
> out. Or get a 
> > "Test pipe"
> > if there is one made for your car. Ether way, nuke the thing.
> 
> DO NOT do this under any circumstances.  Removing emissions 
> controls is a federal (and state) offense; just ask the chaps 
> at a shop in southern New England that was just completely 
> shut down by federal officials for removing catalytic 
> converters and/or gutting them.  The fine is several thousand 
> dollars PER VEHICLE.

I believe that fine is for shops, and that the law, in general, is less
clear for individuals.  Besides, if your state has no visual inspection, and
the car is running properly with good emissions, why leave it in?  Are laws
worth following because merely on account of them being the law?  I assume
you've never exceeded the posted limit at any time in your illustrious
history of audi ownership ? :)

> Despite what Mr. Varosyan says, catalytic converters are 
> there for a reason, and it is extremely irresponsible to 
> remove them (same goes for venting your crankcase to the 
> atmosphere; it's a HUGE source of HC emissions; there's a 
> reason that stuff has been getting put back in the intake for 
> forty years).

I disagree.  It is only irresponsible to remove or alter the emissions
control equipment on your car if doing so would considerably increase its
unwanted emissions.  As said elsewhere, this is not always the case.

> You want to remove cats and/or vent your crankcase to the 
> atmosphere?  You can, as far as I'm concerned, when you're not #$@! 
> ing up everyone else's air.  Until then, given we're all 
> breathing the crap your car does or does not put out- play by 
> the rules.

I believe the original poster claimed that some/his cars do not have
substantially worse emissions running catless.  By your first statement, he
should be able allowed to run with no cat, as he'd not be making anyone's
air any worse.

> > Every car that I have seen without it's cat's shows better 
> numbers on 
> > the emission tests than it did with them.
> 
> Then the vehicles were not properly maintained, the cats 
> dead, the car was tested improperly, or you're making it up.  
> There is no conspiracy.

On the contrary - I know of at least one person with a meticulously tuned
BMW M5 (E28, S38B35 motor) who can pass CA smog with no catalyst (not
visual, naturally).  Note also that the E28 M5 has no air pump, no egr, and
no other emissions sillyness - it just happens to run very cleanly when in a
proper state of tune.  My E28 M5, on the other hand, is not in a proper
state of tune and needed a new cat + O2 sensor to pass WA state emissions.

> > Those things are bogus, much like O2
> > sensors, and only work under certain conditions for certain 
> problems 
> > in a lab.
> 
> No.  Actually, they really do work.  The ECU varies the 
> mixture slightly between lean and rich, causing the cat to 
> load alternately on CO, NOx or HCs...and catalyze them when 
> mixture swings in the opposite direction.

On the overwhelming majority of DME systems, the car runs in open loop at
idle and WOT.. And frankly, many honda models run an ultra-lean
part-throttle cruise mode (15 or 16 to 1 AFR), where an O2 sensor is out of
its useful range.  

NB Oxygen sensors are primarily an adaptive device - they compensate, in
limited situations, for changes in the combustion environment that the stock
programming does not take into account.  Note also that by your own
admission, the o2 sensor doesn't "lock" the car onto deal combustino, it
"hovers" (flutters) around this amount.  It seems reasonable to suggest that
a properly programmed open-loop system could acheive steady state in a
non-decayed combustion environment.
 
> > Japan, the most environmentally conscious country in the 
> world, does 
> > not use cats or O2 sensors for just that reason.
> 
> I'm sorry, but you're completely wrong on this.  Japan 
> introduced very restrictive (at the time) emissions 
> requirements in 1978, which spurred the development of the 
> three-way catalytic converter.  The standards were revised in 
> 2000, which is one of the reasons Honda and Toyota have been 
> cranking out (insert adjectives such as "ultra") Low Emission 
> Vehicles since then (that and the California emissions 
> regulations, as well as "fleet" quotas on emissions; every 
> Prius means another Highlander for Toyota, basically).  They 
> all use catalytic converters and O2 sensors.  Volvo and 
> several other companies now also use radiators with a 
> low-temperature catalyst that works on air flowing through 
> the radiator, making them actually negative emission vehicles.

You've addressed USDM cars - the poster was referring to JDM vehicles.  I
too am suspicious of the claim of JDM vehicles not using cats and oxygen
sensors, although it wouldn't be without precedent - europe didn't start
equipping cars with catalysts until well after they were mandatory in the
US.

As an aside, early cars with 2 way catalysts got poor fuel mileage because
they had to run a bit richer than normal to eliminate NOX (or whatever the
emissionf rom lean combustion are)...the catalysts at the time could deal
with the result of running rich, but not runnign lean.  It's arguable wether
or not we were better off having cars running extra rich just to knock out
one type of emission.  The "US EPA Knows Best" theory doesn't exactly have a
stellar track record, in practice.

In any case, this whole discussion is a bit overboard because it seems none
of the parties are willing to retreat from their positions.  We have "cats
and O2 sensors are always awful, and a total conspiracy", which is patently
false, and we have "cats and o2 sensors are always beneficial, and all laws
must always be followed", which is also patently false.

Why doesn't everyone make nice and admit a more balanced position.  Here's
mine - you can critque if you want

1) Oxygen sensors and catalysts help the majority of cars run as well as
they reasonably can, the majority of the time, assuming the oxygen sensors
and catalysts are functioning correctly.