mleds

I'm trying to register it for the first time in california (org. from NY) and it failed smog as a gross polluter. The NO was off the charts, everything else was within limits. Any suggestions on what could be causing this??

5000CDQturbo

O2 sensor and Cat when were they last changed ?

mleds

I believe it is the orginal cat and I don't know about the O2 sensor. I would tend to believe if the cat was bad the CO would be high and not only the NO - am I mistaken? Also the HCs were fine as well

5000CDQturbo

there are ways to test the O2 sensor / I'm sure more people will comment of the smog test

SF200TQ

Ah! A post about my pet peeve!

Errg. Don't get me started on CA smog (haven't, yet, had an audi-related problem, but...): When I was dealing with a different car, I came across a couple helpful pages... not exactly Audi related, but may give you something to go on? Read down a bit on the page for discussion of what causes high values on which tests...

http://www.artsautomotive.com/thesmogstory.htm

In addition to other suggestions, make sure your car is fully warmed up, but running cool-ish (cooler t-stat (solved one high NOx car I had)), make sure you have clean, fresh oil in the sump (one car I had went from failing to passing after doing nothin' more than changing the oil), maybe new plugs/wires/filters. Run 91+techron, too, maybe.

We can't really adjust our timing, or I'd suggest that, too... and I don't believe we have EGR valves (?) but they also tend to cause NOx problems...

Those My Knowledgeable Than I might be able to provide more help if you post the values for your car and the allowable ranges from the test.

PITA, I tells ya!<ul><li><a href="http://www.artsautomotive.com/thesmogstory.htm">Smog Info</a></li></ul>

auditech1218

Large amounts of NOx are created when the cylinder temps reach over 2500 degrees. The california ones i think had egr however if it came from NY it prolly doesnt. What does the temp gauge read at idle? does all the fan speeds come on? These cars usually create alot of NOx when the fan only works on the high speed and not low speed. The cat could also be something to look at as ive seen quite a few which were hollowed out inside.

mleds

the temp gauge does not always work...... but whenever it does come on it reads about midway. I'm not sure how to answer the fan question - there is a fan that comes on after the car is turned off and I've heard it switch on in traffic but I'm not sure if doesn't come on at other times or if I just can't hear it over the road noise. Is this the fan you are referring to? Obviously I am no mechanic, but I love this car and want to keep driving it - it runs like a top!

duder5kcstq

this has worked on EVERY car or truck I've tried it on so far. Go to your local parts store and buy a bottle of "Guarranteed to Pass" fuel system cleaner. It may sound to good to be true, but so far it is 4 for 4 tries for me, worked every time. It is very important to follow the instructions exactly. One of the cars was my grandmothers 79 Buick Regal 305 V8 that had been sitting undriven for four years. New plugs, cap &amp; rotor, and a bottle of magic. It passed with flying colors, I was shocked. Another one was the old beater frankenstien shop truck Ford that had never passed once in it's whole history. They would just spend the money required by law to try to get it to pass, I believe it was $250. a pop. Last year I told them to try the G.T.P. because if it doesn't work, you get your money back. It passed with near flying colors. Not bad for $20.

audiqv8

I think that it is time to change them.