99a4turd

i replaced my cat with a testpipe a few weeks ago as my cat broke apart and it was cheaper than a new cat no other reason dont care about more power just cheaper. and now i get the o2 code with mil i have tried the non fouler trick and it works for about 100 miles is there a way to delete the rear o2 sensor with vagcom thanks for your help car is 99 a4q 1.8t

4Driver4

VAG-COM is diagnostic software, not tuning software.
You'll need to by a cat to get rid of the light unless you find someone who will flash your ECU with a program that "writes it out".

jschick

no you can not delete the rear 02, you can try adding another fouler and some trial and error or try another sensor, you need to balance the flow past the sensor to fool it. you might need to drill the hole bigger or add another fouler to get the sensor further from the main flow.

99a4turd

that sucks, thanks for the fast reply

jschick

I also remember reading a few years back someone tried adding a resistor to the sensor which worked but I don't recall anything about it. but basically you want the rear sensor reading to be less then the front one which is why the anti foulers work in many situations.

jschick

WOW DID A QUICK SEARCH on O2 sensor mod, and found it for you!!
https://www.audiworld.com/tech/eng53.shtml

you simply add a diode and your done! good luck and let us know how it turns out!

ianbis

diode did not work for me but two stacked foulers sure has, and I now have 224XXX miles on my baby