clancy

I need to replace the B1S2 sensor, after cat. Where is the best place to buy this?

Also, if this does not solve my 16805 code warm up catalyst bank 1 and p0421 efficiency below threshold, then I may also want to relocate the sensors after the cats. Will the stock oxygen sensors reach that far with the standard wire? Or, should I buy the generic sensor that has to be soldered onto my existing connector? I assume if I have to lengthen the wire to reach behind the cats then I might as well just buy the generic one.

Thanks

2.7Lturbo

you want to relocated the sensor after the pre cat or the main cat? i wouldnt touch the pre cat sensors. as for the post cat sensor, if you dont mind splicing the wire, any universal o2 sensor will work.

also according to ross-tech:
Special Notes
When found on the following, there may be a firmware update:
2000 - 2001 Passat with ATQ engine, see TSB 01-07-07 (TPI 2010372)
2000 - 2001 A4 or A6 with ATQ engine, see TSB 26-08-07 (TPI 2013086)
2001 Allroad with APB engine, see TSB 01-08-20 (TPI 2005579)
2001 A4 or A6 with APB engine, see TSB 01-08-34 (TPI 2012357)

make sure you have the firmware update to your car if you have any of the following engine codes

clancy

I am talking about the post cat sensors.

It is my understanding this might solve the 16805 code warm up catalyst bank 1 and p0421 efficiency below threshold. I was adding a pair of anti foulers trying to see if it would resolve this . The driver's side one went in fine. However, in the process of doing the passenger side I think I twisted the wires too much and killed the oxygen sensor. Now I get the code that says it is an open circuit. It is the original one and I imagine the wires were too brittle to be twisted much. I am hopeful that replacing it will solve the 16805. But if it doesn't then I may do the relocation of the sensor.

Soldering the generic oxygen sensor to my existing connector is not a problem. I just don't want to do this if the sensor is not truly the exact correct one. If the only difference is the Audi connector then I will do it. However, if the actual sensor is different then it is not worth saving a few bucks to get one that is just close in specs but not really the same.

2.7Lturbo

on the rears i know it is just a connector difference, bosch has an equipment parts for a fraction of the cost at like autozone, only difference is it needs to be spliced.

now the front o2 sensors - i would go OEM on those as i have not used universal in the past on them.

2.7Lturbo

http://www.autozone.com/autozone/par.../N-jhwtuZ9ixrp

look for the left and right down stream sensor, should be about 67 dollars, looks like the connector might be the same too, so no splicing!

the fronts are so expensive because they are wide-band sensors and we need two of them!

ezveedub

Exact fit Bosch rear O2 sensor is Bosch part# 16978. The Bosch part# 15733 is the universal fit O2 sensor and is cheaper since you have to splice it to the original O2 sensor wiring.

clancy

Thanks to all. Appreciate your quick responses.

2.7Lturbo

thx for the clarification! figured the part that was half the cost would need the splicing