I was wondering what would be the signs of clogged catalitic converter on Audi 100 1989??? Why am i asking? Read what i have started to notice on my car for the last month or so....
Performance is OK for the 2.3L engine but i have the feeling that it is not constant....put in other words, sometimes the car seems to run/accelerate so much easier. Sometimes it feels like i have put 87 octane gas in the tank. The gas that i use is usually 92 and rarely 89 (Shel, 76 or Chevron) So it can't be the gasoline.
Smell.....this one i can't explain because it comes just with or without reason. Sometimes i accelerate very hard from stop to let's say 50 ot 60mph and there is no smell. But sometimes it starts to smell really weird, i guess i can say like rotten eggs(i read that somewhere in the previous posts).(my almost new '99 Toyota corolla have simular smell once in a while too) Sometimes i drive in the mountains and there is no smell at all but sometimes it just comes really strong and in 3-5 minutes it's gone. However, in the last month or so i began to feel this smell more often and SOMETIMES it even comes when i press on the gas on the freeway to go from 65mph to 85+ quickly. Then it is gone.
The car has 125k miles. I haven't replaced any exhaust parts for the last 55k miles except the rear mufler.
Something that made me think about this issue is that i drove my dad's company car two days ago. It's Audi 5000 non-turbo, AT and it's year '84 or '85 with 60k miles more than mine. (~200k) Believe it or not, this old car felt quicker than mine. IS that possible if mine is completely OK? I don't think so. But the old Audi 5000 had a recent exhaust repairs.

Tell me how long the cats on these cars usually last? Are my simptoms comming from the catalitic converter? Is this normal for 10 y/o car?
If i have to replace the cat. , can you recommend good place to get it from? Do i need an original Audi one from the dealer or not? What is a good price?
Should i replace it myself or that's imposible?

Thanks for the help.

DanA100

 

...O2 sensors yet?? Your mixture could be off because of a bad O2 sensor. Try replacing that and see if your smell goes away. If it stays with a new O2 sensor then you MIGHT have a cat. on the way out!!

HTH!!
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Andrew
90 80q
91 90
95 90q

 

a tin can rattling around. Real metallicky(sp?) sounding. I replaced it at a local muffler shop with a high flow cat. Car runs great now. It was about 1/2 the cost of the dealers. You might also check the o2 sensor, like fast928 says.

 

NO, i haven't replaced this sensor since i own the car. I don't know about before that.
OK, here is the stupid question......where should i find my O2 sensor?
I have the I5 engine.
What's Good price for the O2 sensor?

DanA100

 

Yeah, i have that kind of sound too.(mostly when car is cold and when i push it harder) I always thought that this is the mufler again which is only 40k miles old with no rust at all or holes. I was wondering why my car has such a crappy sound especially when it's cold. Can i blame the cat converter in this case??? Or the O2 is still under question?

DanA100

 

the CAT will start to break up and be spit into the exhaust. After some time this will start to accumulate and cause some blockage. Car will begin to feel extremely under powered or "plugged" up. Sometimes the car will not even run at all...

I agree with fast928. Check the 02 sensors first. This would generally be the source of some of your "sulfer" smells due to the car running off mixture. Could also explain the poor running conditions you were having...

As far as the loud metal rattling you are hearing: one possibility is that it is the cat. The other possibility is that it is a bad baffle inside of your muffler. Cheap mufflers tend to have these problems sooner than others...

O2 sensor is located in the exhaust manifold. Looks like a small sparkplug with three wires...

HTH
Steve Ankney
88 5k
Holland, Michigan

 

...where exactly it is located. As Stephen said it's located on the exhaust manifold. On the I5 it's tucked way down there around the one of the half axles near the CV boot.

The easiest way to explain where it's located is to look for the wires that lead to it. If you look along the row of spark plugs...towards the back of the engine bay there is a small metal "platform" located in between two of the spark plugs. On that "platform" there are a few (two, three?) connectors hooked up. Trace the round connector (if I remember correctly)...it should lead to the O2 sensor.

If you can't find it let me know...I'll go look at the engine and explain it again. I might be a little off from memory!!

Price the sensors at a few websites!!

HTH!!
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Andrew
90 80q
91 90
95 90q

 

Sorry, can't help you...I'm a dog person. :P

 

My 92 100cs emits the rotten egg smell after hard acceleration, so maybe it's normal for the stock Cat. The service bulletin came from the Popular mechanics shop manual on CD, (lots of interesting service bulletins).

Anyway, I think Steve had recommended a local muffler shop which can install high flow cats at less than the Stock price. I'll be going this route. I'd also like to keep the pipes from the cats separate all the way to the tips for better flow.

A clogged cat will definitely cause a decrease in performance.

Sam.

 

It's like a honeycomb inside the cat and that stuff break up and starts rattling.