94 Audi 90 CS - failed emission test - Cat Converter?

I recently purchased a 1994 Audi 90 CS with 181000 miles (probably my first mistake).

Anyway, it failed the emission test in Ohio with very high NOx readings. CO and HC were in very acceptable ranges. I was told it is probably the catalytic converter. Well unfortunately, I think the car has two cat converters and they run around $300 each.

Does anyone have any experience with the universal catalytic converters (which run about $90 each) and getting them installed in a

90 CS? Any problems with these and integrating into the exhaust system?

Does anyone have any other thoughts besides replacing the cat conv to reduce NOx emissions? I already changed oil, changed plugs, changed anti-freeze and air filter. None of this helped NOx, reduced CO and HC a bit, but NOx actually went up.

Reply to
bwm
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High NOx does indicate bad catcon.

Aftermarket ones are available - I'm not sure I'd want to trust a system to a cheapy universal, but more toward an AM one from a reputable Audi parts supplier, with brand names like Bosal or Stromung.

A high-mileage Audi will serve you well, as long as you keep on top of those small things. A well-kept older Audi can keep it's resale value for a long time, even with high miles - as long as you keep it in tip-top shape. Let it go, and you'll be looking at a valueless money-pit.

Now for the embarrassing question: why didn't you get a pre-purchase inspection done? No matter what brand of used car, this is an essential step. Once you found out about the bad catcons, you could have negotiated a better price to cover the cost of replacement.

Still, unless you spent WAY over blue book, even with the bad catcons, I think you'll find that used Audis provide a lot of bang for your used-car buck.

Good luck, and report back when you get her fix up. :)

E.P.

Reply to
gcmschemist

bwm, Mistake? 181k miles is not a heck of a lot - what matters if they were "hard or easy" miles - aka - how faithful the previous owner(/s) was to the maintenance schedule of the car. How old are the plug wires? How old is/are the oxygen sensors? When the e-test is run, the car should be at operating temperature - that means that you should take it out and drive around for a while, then take it to the test facility and do the test without letting the car cool down. If the cats are cool - the car has sat for hours before the test and only run briefly before the start of the test, the elements will not have heated up enough and will not be working. Cheers! Steve Sears

1987 Audi 5kTQ 1980 Audi 5k 1962 and '64 Auto Union DKW Junior deLuxes (SPAM Blocker NOTE: Remove SHOES to reply)

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Reply to
Steve Sears

The message from bwm contains these words:

My 94 100 Avant's got nearly ¼million on it - hardly run in.

Reply to
Guy King

I love posts like this; I plan to keep my 98.5 A4 2.8 for as long as she'll go because even with the expensive repairs occasionally, she's still a lot cheaper than a new car and a lot nicer to drive than most cars. We're at almost 89,000 miles, and counting (going in for the

90k maintenance tuneup next week).
Reply to
KLS

"" wrote: > bwm wrote: > > I recently purchased a 1994 Audi 90 CS with 181000 miles > (probably my > > first mistake). > >

gcmschemist, thanks for the reply.

To answer the embarrassing question, well... I was out of the country and returning to the US, so I bought the car on eBay, and for the price I paid for the car, it was worth it to me if the car did not last me long. I know I still could have had the car looked at, but I guess I was just lazy. Lesson learned.

Reply to
bwm

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