forum.audiv8.com Foren English Audi V8 Forum Lambdasonde / o2 sensor

Please help. I have read all the posts I can find on these o2 sensors but can't seem to find my problem. The car starts and runs fine. As soon as it warms up, it begins to smoke black, and when holding a steady speed the motor really acts up. As if someone were tapping the gas pedal really fast. The engine pulls fine while accellerating and while slowing down, only when trying to maintain a steady speed. I went to the Audi dealer and they said the o2 sensor is bad and the computer is bad. I replaced the o2 sensor with a new one and tried a working computer form a good car. No change. We diagnosed the car again and again I was told the o2 sensor is not giving any readings. They suggested that perhaps the o2 sensor is not getting any power.

Does anyone know how to check for power and if there is no power coming, does anyone know werhe it should be coming from?

I am really up to my ears with this car and just want to be able to sell it. The rest of the car is top notch.

thanks in advance for your help!!

Hi, Dastin
You can disconnect black wire from O2- sensor.
If engine works good and ECU has no faultcodes,
you may to maintain car in this way. CO is 1.5%.

Good luck,
Dmitry

Must probably one or more of the bunch of sensor around the engine gives wrong signals. Did you read out the faultcodes?
The lambda (O2) sensor is the reason for alternating accelleration but not for black smoke. And a faulty computer would give you more headache.
Good luck
Michael

I am now looking at the possibility that the computer I tried was in fact the wrong one. My computer has an Audi # ending with HA and the computer aht we tried has no letters at the end of the number but the number was the same. Also the Bosch number was different in the last 3 digits. I will get the exacxt numbers and post them.

Does anyone know of a reference where I can look up what these numbers signify?

Thanks again. You guys are really great.

OK here I am again.

My computer has the following numbers
VAG 441 907 404 HA
Bosch 0 261 200 198

I tried a computer with the following:
VAG 441 907 404
Bosch 0 261 200 183

Can anyone point me in the direction to see if this computer will work. i got the same results with it and don't know if that because its the wrong part or if its because the problem is not in the computer.

I will ask AUDI for the fault codes tomorrow.

If anyone has a 441 907 404 HA in good working order for sale....I may be very interested