Everton

Cleared my O2 faults then drove car for about 5 min. Check engine light stayed off. Shut engine down. Upon restart the CEL immediately came back on. Pulled the following codes:
Control Module Part Number: 4B0 907 551 K
Component and/or Version: 2.7l V6/5VT G 0005
Software Coding: 06612
Work Shop Code: WSC 02325
VCID: 2C5D1429DC10169
2 Faults Found:

17526 - Oxygen (Lambda) Sensor Heating; B1 S2
P1118 - 35-00 - Open Circuit
17522 - Oxygen (Lambda) Sensor; B1 S2
P1114 - 35-00 - Internal Resistance too High

Readiness: 0010 0101

Cleared codes again and then drove 90 miles (interstate) without shutting the engine off. CEL stayed off and car performed well. Car sat for about 2 hrs and upon restart the CEL immediately came back on. I would assume that those two faults were once again the issue.

Is this an indicator of some electrical/relay/ground issue and really not a passenger side-back O2 sensor malfunction? Any help would be appreciated.

Just Me

Dunno - the open and the hater faults are likely connected. Open could be leading TO it or IN it. Or so logic dictates, i've never chased one down. yet.

G

eejimm

Short answer - yes, probably.

I would look at either a loose/corroded connector, or an intermittant wire. These kinds of things are a bear to find. The tip-off is that you didn't get the CEL/codes while the car stayed hot. Metal, and copper in particular, expands when it heats. A slight break in a wire or wire/connector interface can "heal" itself when it warms up because the copper expands and makes contact. When it cools down, it shrinks again and opens up the connection.

Sometimes you can find the problem by flexing the wire near the connector to see if the connection comes and goes. You can also get a can of freeze-spray (used in the electronics industry just for this) to chill specific places once the car is hot to see if the problem comes back. Your problem is exacerbated by not knowing exactly when the ECU is going to "see" the problem so you know it's there.

You could also check the individual wires connector pin to connector pin with an ohmmeter to see if there's a break. Tedious, plus you have to get to both ends of all the affected cables.

Good luck
Jim

SloopJohnB@mac.com

I dunno...seems like horses, not zebras. Why not just replace the 02 sensor?