check engine light & cat converter

[paultn]

bought a 2004 A4 1.8T w/99000 miles. runs great but seller said he would fix the check engine light because it was nothing serious; as it turns out the light is on because of either a faulty O2 sensor OR needs a new CAT. Got a quote from an auto import "specialist" for $1900 to do that. Any one have experiene with these CATs in the A4?

[Mawhitey]

thats a rediculous price, a high flow performence cat costs only a few hundred dollars. Labree springs to mind

[Rydal]

Originally Posted by paultn

bought a 2004 A4 1.8T w/99000 miles. runs great but seller said he would fix the check engine light because it was nothing serious; as it turns out the light is on because of either a faulty O2 sensor OR needs a new CAT. Got a quote from an auto import "specialist" for $1900 to do that. Any one have experiene with these CATs in the A4?

Sounds epensive. I have two O2 sensors on my A4. One on the engine manifold and one at the exit of the CAT. If the CAT is not working the Cat O2 logs this by switching on the engine management symbol. Also an exhaust leak between the engine manifold and the Cat (usually at the flexible coupling)would also cause the light to come on. If no leak in the exhaust sysyem is evident then it could be a faulty O2 or your Cat needs replacing. Cats have come down in price so you should be able to purchase and instal one for about $600 max. The Cat may come complete with engine manifold exhaust pipe and flexible coupling. Hope this helps. Rydal

[Reddog30jen]

I am also having the same problem with my audi. Recently my check engine light has started comming on and off. I went to my audi dealership recently and they told me that the error codes also were O2 Sensor, Cat Convertor, and also Purge Valve. I am curious about this one because maybe it is just a leak or something causing error codes? My car was lowerd before I bought it and I bottom out ALL the time, so maybe something broke. Any help on this one is appreciated. I really don't feel like changing all this stuff if it's not necessary. Audi gave me estimate of over $2600 to replace this stuff.

[Rydal]

My EMC light kept on coming on. I took it to Audi who told me it was the O2 sensor playing up which usual meant a gasket leak or a faulty sensor. I took the car to a local garage who confirmed that the gasket seal on the engine manifold was blowing at high revs. Asked them to fix the leak and not had a problem since. Hope this is of help. Rydal

[rockstar949]

i have a 99 audi, i took it to get the oil changed and now the radio doesn't work the a/c won't come on and the rpm doesn't go past 1500, and like 15 miles an hour when i have the gas pedal all the way down, then when i hold it down it will get up but jerks ALOT. i changed the battery and they did a test on all of that it's good, they tried to test the engine at 2 different mechanice but they can't get it to link u. i don't want to drive it to the nearest audi dealer, its like an hour away and i don't want to mess something up even worse than it already is....anyone have any suggestions on what the problem might be?

[Rydal]

Sounds as though you have a serious problem. The erratic running of your engine can be caused by your engine management unit. Sorry can't help more. Dave

[docurley]

Sound like the coolent sensor my be causing some of your problems (cheap and easy fix)

[rockstar949]

thanks guys, i took it in today and there were a couple of fuses that were blown which is why the a/c and radio didn't work, and the reason the car was actin like that was because of an ignition switch of some sort that went bad, i don't know too much about vehicles but they switched it out it took a few hours and $250, guess it could have been alot worse