My friends '08 A6 quattro is throwing these codes (only 36K miles). I've searched the forum and found almost nothing. Any help as to where to start would be great.

I got the descriptions from a VW site (http://forums.tdiclub.com/showthread.php?t=167421). HELP!

P2247 O2 Sensor Reference Voltage Circuit/Open, Bank 2 Sensor 1
PO136 O2 Sensor Circuit, Bank 1 Sensor 2
PO155 O2 Sensor Heater Circuit, Bank 2 Sensor 1


It has to do with the O2 sensor obviously, but....where to start?

 

Thsi car still has factory warranty, I would take it in and get it fixed. The ECM sends out a reference voltage (about 5V) and the sensor veries resistance to it to make the signal. If the reference voltage is wrong, the ECU is not getting it to the sensor. It needs checking. Thsi type of thing happens to flooded cars so get it to the dealer, an 08 with low miles should not do this unless the harness was damaged or the ECM flooded.

 

Ditto... wouldn't bother looking at it. Just take it back to the dealer.

 

Thanks for the insight. I know it is under warranty but my local stealership always tries to manipulate the situation. Go in for a check engine light and who knows what they will say is wrong. I just wanted to make sure I knew the basics. Cheers!

 

There are very few situations under the full factory warranty that the owner would have to pay for this repair, unless there were signs of flooding or hammer marks on the parts.