failed emissions

Jeff Doble jeff at awdriven.net
Tue Apr 29 13:41:44 EDT 2003


Dave I had the same thing happen on my 4ks (1.8L) a couple months ago.  Except my HC's were at least twice what yours are!  They were over 1000 IIRC.

First thing I did was have the motor decarboned using a Motorvac (http://www.motorvac.com/mcs245_pg.html) machine.  It dropped HC's to about 500 but the car still wouldn't pass.  The carbon buildup in the cylinders was probably causing a bad spark so the combustion was incomplete.  This made the biggest change in my emissions.

After fixing a small vaccuum leak the HC's fell even more (to around 400) but still the car wouldn't pass.  I've now been told that the cat is probably bad so I should replace it.  However, here in PA, there is a clause in the emissions testing that if you spend (I think) $150 trying to pass emissions you can get a waiver which means you are legal again.  Well, I spent $150 for the motorvac, vaccuum, and some other small tweaks so I got the emissions waiver sticker which is good until next year.  By then I'll try and get a new cat on the car.

If you've spent money since the original test and can prove it with receipts it's worth a shot asking about the waiver.

Funny thing is, last year the car passed emissions (barely) and since then I've replaced the plugs, wires, O2 sensor, distributor cap, ignition rotor, cleaned the intake/throttle body, and fixed an exhaust leak and now the car won't pass.  Hmmmph.

JD

>
>--- Dave Hord <spokes at the-wire.com> wrote:
>> Hey all,
>>
>> Patient: 1987 Audi 4000 quattro
>> Problem: Failed Emissions Test.
>>
>> Test is done at 2500rpm (in neutral) and Idle RPM
>>
>> I don't have my first emissions test in front of me, but after
>> failing the
>> first test I looked in the archives and everything there seemed to
>> point
>> towards needing a new Catalytic Converter.  Easy enough, we make
>> them.  I had a
>> new O2 sensor in my desk, so I installed that as well.
>>
>> My new test this morning was a fail with pretty much the exact same
>> numbers.
>> Todays test:
>>
>> 2500RPM
>> HCppm: Limit=300 - Reading=312
>> CO%:  Limit=1.5 - Reading=8.76
>>
>> Idle
>> HCppm: Limit=300 - Reading=580
>> CO%:  Limit=1.5 - Reading=10.07
>>
>> Anyone have some bright ideas as to what I should be trying next, and
>> where the
>> problem might lie?
>>
>> Please CC me as well as the list, as I am switching to not-recieivng
>> the list
>> due to work being rather hectic this month.
>>
>> TIA,
>>
>> -Dave
>>
>> --
>> 86 4ksq 266,600km new to me as of March 5th 2003... will it stick
>> around??
>> 89 90q  330,000km as of Feb 26th.
>> Rally Conversion...perpetually in progress...
>> Roll cage shots available at:
>> http://home.the-wire.com/~spokes/rollcage/page1.htm




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