Catalytic Converter Probably Gone- 04' A4 1.8T

[johnny quattro]

Two cents worth! Make sure it is a failed cat first. There are 2 x O2 sensors, one before (bank 1), and one after (bank 2). The on board diagnostics in the ECM continuously polls these 2 sensors and compares the values. Given a sufficient difference the check engine light will illuminated and DTC for "failed cat" flagged. Before you condemn your cat, run a bottle of Can Tire Fuel System Treatment (Xtra concen $5) through your tank to ensure the sensor is clean. Before anyone asks, no I don't have shares in Crappy Tire!

[audigemini]

Quote:

Originally Posted by johnny quattro

Two cents worth!

Make sure it is a failed cat first.

There are 2 x O2 sensors, one before (bank 1), and one after (bank 2).

The on board diagnostics in the ECM continuously polls these 2 sensors and compares the values. Given a sufficient difference the check engine light will illuminated and DTC for "failed cat" flagged.

Before you condemn your cat, run a bottle of Can Tire Fuel System Treatment (Xtra concen $5) through your tank to ensure the sensor is clean.

Before anyone asks, no I don't have shares in Crappy Tire!

Hi John, I did run the Cdn Tire Fuel Injector cleaner through. is that what you mean?

I am certain it helped my car. it feels like it is performing better

My engine light is on, but car is running fine.

Does a faulty Cat cause mileage to be higher than normal?

Thanks

[johnny quattro]

Hey Dave,

Yes to the Can Tire Fuel Injector cleaner, althrough make sure it is the Xtra concentrated, fuel system cleaner (they usually come in 2 packs for $10).

It is a good routine maintenance item to run a dose through your system at every 3 or 4 gas fill ups.

It definitely improves performance and keeps the whole fuel system clean and free of carbon deposits.

If your engine light is on, and the car is running fine, run a second dose through.

Is the engine light steady or flashing?

If you have the OBDII reader, reset the trouble code.

If it is your cat, the light will come on again after a few miles.

If it is only dirty O2 sensors, the second dose should clean them and the light should go out after a couple of tanks of gas.

A faulty Cat is mainly a polution issue, but can cause mileage to be higher than normal.

Hope this info is useful?

John

[audigemini]

Quote:

Originally Posted by johnny quattro

Hey Dave,

Yes to the Can Tire Fuel Injector cleaner, althrough make sure it is the Xtra concentrated, fuel system cleaner (they usually come in 2 packs for $10).

It is a good routine maintenance item to run a dose through your system at every 3 or 4 gas fill ups.

It definitely improves performance and keeps the whole fuel system clean and free of carbon deposits.

If your engine light is on, and the car is running fine, run a second dose through.

Is the engine light steady or flashing?

If you have the OBDII reader, reset the trouble code.

If it is your cat, the light will come on again after a few miles.

If it is only dirty O2 sensors, the second dose should clean them and the light should go out after a couple of tanks of gas.

A faulty Cat is mainly a polution issue, but can cause mileage to be higher than normal.

Hope this info is useful?

John

Very useful!

I did reset the codes and the engine light did come back on..lol

Maybe this is why my car gas mileage reader goes to 40 L / 100 before it settles down, when I accelerate from a stop sign.

I could try a couple more times and re set the codes and clean my engine with the Crappy Tire stuff and see what happens

If that doesnt work, I guess I will have to decide what type of Cat I should get and where from?

Any thoughts?

Thanks!

[johnny quattro]

Yep, try a couple more doses of the crappy tire stuff (Xtra concentrated).

I think you should not be concerned about the 40L/100km on acceleration.

That's exactly what mine shows, the same ever since I have had my '04 A4 Q 1.8T, now with 90k on it.

If you do eventually have to replace the cat (I wouldn't give up on it yet, if I were you), no thoughts re source yet.

My son just had a cat back complete system installed for $2,800 at Pfaff Audi Vaughn (ouch!).

I will keep an eye on the martketplace.

[audigemini]

Hi

I recently learned that for the 1st 3 years/80,000kms when my car was serviced at the dealer, they used regular engine oil. 2002/2003/2004. This was all part of the AUDI Care service warranty.
This was spec at that time.
Then a letter came out from AUDI Canada to only use 502 synthetic oil.

I am wondering if the fact that they used regular engine oil for the first 3 years of my ownership. has caused or contributed to my faulty cat converter

(assuming my cat is faulty..which I am still working on with cleaners etc)

Any thoughts?

Thanks

[geerup]

My cat converter needs to be replaced as well. Found out after I got a MIL light and checked the code with an ODB reader. Code was P0431 Warm Up Catalyst Efficiency Below Threshold.

I checked my warranty booklet and found under emissions control that my car is covered for 8years/130000Kms. Great news since I'm just coming up to 127000Kms. Took it to audi and they said everything is covered.

[johnny quattro]

Quote:

Originally Posted by audigemini

Hi

I recently learned that for the 1st 3 years/80,000kms when my car was serviced at the dealer, they used regular engine oil. 2002/2003/2004. This was all part of the AUDI Care service warranty.
This was spec at that time.
Then a letter came out from AUDI Canada to only use 502 synthetic oil.

I am wondering if the fact that they used regular engine oil for the first 3 years of my ownership. has caused or contributed to my faulty cat converter

(assuming my cat is faulty..which I am still working on with cleaners etc)

Any thoughts?

Thanks

The problem always is getting the dealer to admit it!

How many klick you got Dave?

[audigemini]

Quote:

Originally Posted by johnny quattro

The problem always is getting the dealer to admit it!

How many klick you got Dave?

Hi Johnny

I have 250,000 kms now

Running really well ....!


Dave

[johnny quattro]

Quote:

Originally Posted by audigemini

Hi Johnny

I have 250,000 kms now

Running really well ....!


Dave

250 and running well? That fuel system cleaner can really make a difference!

Don't forget to do a TBA every couple of weeks also.

As the gunk gets cleared from your system, you have to re-align your throttle body periodically.

I don't think that using conventional oil can contribute to ruining your cat.

That would only contribute to sludge build up.

If you were burning oil because of excessive engine wear, that would eventually ruin a cat.

Keep dosing with the cleaner every two or three tanks (it works out at $3 a tank extra cost, but well worth it) and hopefully the CEL will stay reset.