UnoDosTurbosQuattro

2001 allroad 2.7T Tiptronic, Key-Com, VAG-COM Release 504

Fault Code which shows up most often:
17866 - Exhaust Gas Temp Sensor 2 (G236): Short to Ground P1458 - 35-00 - -

After resetting fault code, it usually comes back the same way, or sometimes instead it is
17865 - Exhaust Gas Temp Sensor 2 (G236): Open or Short to Plus P1457 - 35-10

Note I had a blown diverter valve on bank 2 (driver side), so I replaced both DVs. But fault P1458 still comes back.

So I logged some data, for instance Block 115 with block 112:
<img src="http://pictureposter.audiworld.com/80906/egt_sensor_data1.jpg">

Per Bentley section 26-27, "Regulation does not begin until temperatures above 980 C" and "During oscillation stage, values around 1025 C may be displayed briefly" and "During oscillation stage, enrichment values of 25% may be displayed briefly"

---Why aren't the temp readings more consistent between banks 1 and 2 - should I assume the 940 reading and &gt;1000 reading on bank 2 is due to a faulty EGT sensor?

I also logged blocks 220 and 221. <img src="http://pictureposter.audiworld.com/80906/egt_sensor_data2.jpg">

Even though I was &gt;5000RPM and Load &gt;100% (per Bentley WOT recomendations), the "OFF" would not turn to "ON" in field 4. Also the duty cycle for bank 2 was either 0 or nearly 100%, while bank 1 was a steady 5.1%(not 42% +/-10%?)

---Shouldn't field 4 turn "ON" per Bentley section 26-28?
---Why isn't bank 1 duty cycle ~42% per Bentley?
---Are the wacky bank 2 duty cycles more evidence of a bad EGT sensor?

Maybe the bad diverter valve on bank 2 caused a problem with the EGT sensor on the same side?

Sorry for all the whiny questions. I assume I should just replace EGT on bank 2, but thought I'd ask around first, as the sensor is ~$200 and bank 2 is impossible to access - so I'll need to have the dealer do it ($$).

Thanks in advance for your comments or suggestions.