Subject: Failed emmissions High HC

Dr. Adam Gratz dradamgratz at
Tue Jul 27 23:45:45 EDT 2004


High hydrocarbons (particularly that high) usually mean an intake leak. 

1) Take a look at and then snug up your spark plugs (I really doubt that
they are the culprit). Don't worry, if there is an issue it will be obvious
and you will see it, heavy carbon or oil build up on one plug over the
others.  Price: Free

2) Buy a small propane canister at home depot or Harbor tools and with a
length of fuel line or whatever on the tip, turn it on and go poking the end
around the intake manifold and the throttle body etc.. Don't forget the fuel
injectors! If the idle climbs then smoothes out, you've found your leak.
Price: $18 - can also be done with brake cleaner spray, but I prefer the

3)Test your coil and wires. Rare but hey, it could happen. Price: Free

4) Replace that O2 sensor. The O2 sensor is only good (per Bosch) for 60k
miles. Simply unplugging it will not give you any real info - I just found
some universal 3 wire Japanese ones for $65. 

5)Put in a can of BG-44 fuel cleaner, found at some nappa stores and most
independent shops. Try adding to an empty tank and then add 4-5 gallons and
drive it like you mean it! Price: $14

6)Change that dirty black oil! Price: $20

7) Make sure your cat is good and hot before you sniff the tail pipe. Cold
catalyst don't catalyze to well, now do they? Cost: Free

8) After all this fails, replace the cats like I had to do......Cost: a
second Mortgage should cover it

My best tricks, exposed,

Dr. Gratz
1991 200 20v Avant (thank you Drew Lipner)
1996 A6 12v Q Avant
1988 5000 TQ Avant (I miss you old bean)
1990 100 Auto grunt car


Message: 2
Date: Tue, 27 Jul 2004 12:50:28 -0700
From: Chuck Pierce <cpcycle at>
Subject: Failed emmissions  High HC
To: 200 list <200q20v at>
Message-ID: <4106B204.808 at>
Content-Type: text/plain; charset=us-ascii; format=flowed

Well gang I now have a challenge to solve.
I could use some wisdom on where to start on looking for the cause of my 
high hydrocarbon output
It measured:
193ppm with a 120ppm max at low speed (801 rpm)  REALLY BAD 103ppm with a
140ppm max at high speed (2568 rpm)  not good but passing

I found a message with a couple of things to check
1. O2 sensor  ( new 9/02)
2. Check and clean injectors
3. Replace/clean spark plugs ( new 9/02)
4. New cats. ( new 9/02)

What kinds of codes would I be looking for when I down load them? I also
read something about a temp sensor that could cause the ECU to go 
into certain modes by its failure.

Wisdom appreciated
Chuck Pierce
91 200 tq 20v Avant


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