O2 Sensor Codes - Custom Exhaust

[valliyappan]

Just bought a 07 RS4 with a custom exhaust on it, borla muffler with custom piping and custom downpipe with cat delete. I can see that the both pre and post cat O2's are installed but I got lots of codes. I haven't done anything more than scan for codes and physically look (still digging out of this snow storm).

What do you guys think? Where should I start looking? I do have VAG-COM so I plan on monitoring the O2 sensors.

000313 - Oxygen (Lambda) Sensor B1 S2
P0139 - 004 - Response too Slow - MIL ON

004372 - Oxygen (Lambda) Sensor; B1 S2
P1114 - 008 - Internal Resistance too High - MIL ON

000320 - Oxygen (Lambda) Sensor B1 S2
P0140 - 004 - No Activity - MIL ON

000054 - Oxygen (Lambda) Sensor B1 S2: Heating Circuit
P0036 - 004 - Malfunction / Open Circuit - MIL ON

004416 - Oxygen (Lambda) Sensor; B2 S2
P1140 - 008 - Internal Resistance too High - Intermittent - MIL ON

000342 - Oxygen (Lambda) Sensor B2 S2
P0156 - 008 - Malfunction in Circuit - Intermittent

000345 - Oxygen (Lambda) Sensor B2 S2
P0159 - 004 - Response too Slow - Intermittent

[BenSti]

Your O2 sensor is actually bad, it's possible you damaged the wiring or didn't fully connect it. Replace the secondary O2 sensor.

[valliyappan]

Your O2 sensor is actually bad, it's possible you damaged the wiring or didn't fully connect it. Replace the secondary O2 sensor.

Would you say both? Bank 1 and 2 both are reporting codes but slightly different once.

[BenSti]

Would you say both? Bank 1 and 2 both are reporting codes but slightly different once.

That's what it looks like. The internal resistance and circuit malfunction indicate that there is an electrical problem with the sensor. The secondary sensors aren't too expensive.

Cyl 1-4: 022906262BM
Cyl 5-8: 022906262BQ

Don't buy the cheap ones, buy either Genuine Audi, or Bosch/Denso models.

[valliyappan]

That's what it looks like. The internal resistance and circuit malfunction indicate that there is an electrical problem with the sensor. The secondary sensors aren't too expensive.

Cyl 1-4: 022906262BM
Cyl 5-8: 022906262BQ

Don't buy the cheap ones, buy either Genuine Audi, or Bosch/Denso models.

So decided to replace 1 sensor at a time, since B1S2 (Cyl 1-4) had more code I decided to replace that one, order that one Bosch 16383. Although I checked the resistance of the sensor I pulled (pin 1 & 2) and its reading about 9 ohms (above 20 ohms indicates a defect) based on this article (http://www.audiworld.com/tech/eng101.shtml ) the heater elements is good. Just cleared the codes, time will tell if the new sensor fixed the issue.

Now looking to order the B2S2 (Cyl 5-8) but I am getting conflicting information amazon says Bosch 16385 is the sensor and on the Bosch website it says 16136. Anyone use Bosch O2 sensors before?

Also thinking about using a O2 sensor spacer/spark plug defouler, looking around the web seems like people use this method when doing a cat delete.

[komseh]

Valli, it's a good idea to stick with OE on the rear O2 sensors. You can get them for a good price from Jim Ellis Audi.

Go to http://jimellisaudimariettaparts.com...?siteid=218759

Search for part numbers:
022906262BM (cyl 1-4)
022906262BQ (cyl 5-8)

[valliyappan]

Thanks for the recommendation but the more I look online I'm not so convinced that the O2 sensor are bad, I hope it's as simple as that. I am planning on driving the car for a bit today and then using the graph tool with VCDS to see the sensor response.

[valliyappan]

So drove it for about 20 miles today, check engine light came on, looks like only B2S2 is reporting now. Looks like it is bad O2 sensors.

[BenSti]

So drove it for about 20 miles today, check engine light came on, looks like only B2S2 is reporting now. Looks like it is bad O2 sensors.

Those codes literally only tell you the O2 sensors are bad...

[valliyappan]

Good news, no check engine light so far, 100 miles on the new Bank 2 OEM O2 sensor, 200 miles on the new Bank 1 Bosch O2 sensor. I think the old O2 sensors got fouled up due to the lack of the cat. Thanks for the help.

OEM Part #
022906262BM (cyl 1-4)
022906262BQ (cyl 5-8)

Denso Part #
234-4849 (cyl 1-4)
234-4832 (cyl 5-8)

Bosch Part #
16383 (cyl 1-4)
16385 (cyl 5-8)

[ohammoud]

I just installed a CTS Turbo Downpipe, I put some spacers on for the 02 Sensors, but I'm still getting a 000054 Code.
It says this exactly: 000054 oxygen (lambda) sensor b1 s2: heating circuit, malfunction / open circuit
Does anyone have any ideas?

[CrickiKaze]

Denso bank one is not it, different style. Decided to try it and got a code for high resistance IIRC. Will order the Bosch bank 1 later.