help with o2 sensor non fouler mod

[judeman]

Greetings all,
I'm hoping someone may be able to shed to light or help me out with my current situation. Completely stock 01' S4 159K. My cats are bad per engine codes. Also had a code for bad bank 1 primary o2 sensor. I then replaced the bank 1 primary sensor. With hopes off not replacing the cats, I purchased a package of 2 spark plug non foulers. I drilled each of them out with a 1/2" drill bit. I have placed one drilled out non-fouler onto each of the two secondary o2 sensors. I wen tot get inspected with a mechanic buddy of mine an fit failed with the o2 and cat monitors nor ready. So I drove the car for 150 or so miles and all was good, no engine lights. Bring it back fro inspection and it passes. awesome On my way home from the inspection, just a few miles, the mil light comes on. I get home and read the code… P1176 Now I understand this is for bank 1 secondary o2 sensor limit attained. My question is what exactly does this mean?
Did placing the non foulers on the secondary sensors trip it? I still have the original bank 2 primary sensor in keep in mind. Is the new bank 1 primary sensor reading so much better than the original sensor that now the limit is attained across the cat? I am only seeing p1176 and not p1177 for the bank 2 sensor limit.
After asking around and doing some more research, I have seen many people doing this mod on gutted dp's and requiring two nonfoulers stacked, with one drilled out, and one not. Is there a chance my bank 1 cats are damaged to the point that I will need this? I am using single non foulers right now.

Any help would be greatly appreciated.
Judeman

[zillarob]

The foulers can be hit and miss.
Best way is to just get in there and code them out. http://s4wiki.com/wiki/Tuning

[seanj130]

Ok- How is your gas mileage?

It took 2 spark plug non- foulers to get it just right. I have heard some people doing it with one.

[nate00s4]

I had a similar issue, I ended up coding the rear out and soon found my pre cats had been slowly going out and was told that the reads often throw codes because the pre cat sensors are going out. I replaced both pre cats and no more issues.
Hope this helps.

[nate00s4]

That the rear often throws codes when the pre cat 02 s are going out. It cost roughly about 130 for both, universal 02 sensors. And I still use the defoulers for the front to keep a longevity for both.

[ddillenger]

Relocate the rear sensors to behind the main cats if you don't want to code them out.

[zillarob]

And I still use the defoulers for the front to keep a longevity for both.

Not sure that is a good idea on the fronts.

[LINDW4LL]

Not sure that is a good idea on the fronts.

+1

[judeman]

Thanks for the replies guys. I will have to do some research on the idea of coding the rear ones out. I had never heard of that. After replacing the bank 1 primary 02 sensor my fuel milage has come back up from ~19 to ~23. I may need to replace the bank 2 primary sensor, but that shouldn't be causing a bank 1 secondary sensor code. Also simple enough to try a stacked non fouler on the bank 1 side and see how things work.

Zilla and Nate, how is the code out procedure? Seems like it should be pretty simple, did you code it through VAG-COM? Anyone else have experience with coding the rear ones out? sounds like it would be the best bet.

Thanks again-

[zillarob]

What are the specs on your car, what ecu? Tune?

[ddillenger]

Zilla and Nate, how is the code out procedure? Seems like it should be pretty simple, did you code it through VAG-COM? Anyone else have experience with coding the rear ones out? sounds like it would be the best bet.

Thanks again-

http://s4wiki.com/wiki/Tuning#Rear_O2_Sensors

[judeman]

car is bone stock so its a factory tune on the M-box ecu-

[zillarob]

That is the easiest one. All you need is a generic or vagcom cable, tunerpro, and nefmoto flasher.
Think there is a checksum fixer over there also. Might see if you can get galleto up and running first, just to be safe.

This codeout is easy and a good way to get your feet wet with this stuff. May look like a foreign language at first, but will start making sense as you go through it.

[Breppinq]

That is the easiest one. All you need is a generic or vagcom cable, tunerpro, and nefmoto flasher.
Think there is a checksum fixer over there also. Might see if you can get galleto up and running first, just to be safe.

This codeout is easy and a good way to get your feet wet with this stuff. May look like a foreign language at first, but will start making sense as you go through it.

Im literally about to devote the rest of my sunday to reading on this stuff.. at least till walking dead starts

[judeman]

excellent, sounds like I have a good project for t-day weekend. Thanks for the help-