No WB O2 - Craig any ideas?

[tazgn]

I posted this resently, but didn't get any definite ways to go. I now have a lot more data. What's happening is my ECU isn't seeing the WB O2 all of a sudden. I've had problems with the indicated A/F "locking up" on some random number before. But here is some data I just got. My ECU serial number is 714.

Key on, car off, WB O2 connected
UEGOS 1.12-1.10
UEGO 3.53
UEGOR 2.49-2.51
Diag A 1275 one time, 1285 second time

Key on, car off, WB O2 NOT connected
UEGOS 0.80
UEGO 3.51
UEGOR 4.98
Diag A 2545

Key on, car running, WB O2 connected
Initally after starting :
UEGOS 0.47
UEGO 0.84
UEGOR 2.47
Diag A 1275

Key on, car running, WB O2 connected
After running about 1 minute :
UEGOS 1.12-1.18
UEGO 3.53
UEGOR 2.49
Diag A 1295
Code 8

Key on, car running, WB O2 NOT connected
UEGOS 0.82
UEGO 3.53
UEGOR 4.98
Diag A 2545

The WB O2 sensor is ALWAYS 0, and I never see the lamda symbol on the bottom right corner. I also tried some older programs to see if I screwed up something in the program, but got the same results. The A/F indicated now is 0.00 90% of the time. Sometimes when I start the car it will lock into some other number, but it will never change once the car is started.

ANY ideas would be VERY much appreciated. I did just rebuild the motor so I was thinking maybe a broken wire somewhere, but it worked initially after the rebuild.

Thank You for ANY help.
Derrick

 

[tazgn]

Any of the other experts have any ideas?

Derrick

 

[tazgn]

I did a search for related problems like this on here, and there are a bunch. But the wierd problem I have is that C-Com is NOT showing the WBO2 lambda symbol. I've now spent a couple weeks trying to solve this, and I'm at my wits end now.

Here's a suggestion though. Since there are MANY of us with similair problems with this, how about a little technical discussion of UEGO, UEGOR, UEGOS and anything else that may help people resolve this. And what are the typical signs of a failed O2 sensor?

Derrick

 

[JCotton]

Mornin Derrick,

Sounds like you are havin some problems there..... at least the weather should be good. Did you check the set up parameters to make sure the O2 was enabled? Also are any of the uego numbers in red when you check them? Did you take out the sensor and shake it, see if there is any rattling around going on?

 

[bruce]

Originally posted by JCotton
Did you take out the sensor and shake it, see if there is any rattling around going on?

Rattling sound?.
I'll pay shipping to get one that rattles. I'd like to autopsy it.

 

[norbs]

I have one you can cut apart, not sure if its a rattler or not though.

 

[tazgn]

Jack,
Yep, the weather is still the "same" out here as it is every day of the year... But, nope, none of the values are in red. In fact I don't have any values at all coming up in red. I will try the removing the sensor and listen for rattling parts. The thing getting me the most now is that C-Com isn't recognizing a WBO2 sensor at all, yet the values of UEGO, UEGOR, and UEGOS are all different with the sensor plugged in or not.

Oh, yep. the O2 option is on. In fact I loaded in some old programs to make sure I didn't screw up something while tuning the program, with the same results.

Thank You,
Derrick

 

[tazgn]

Craig is back.

 

[Craig Smith]

Originally posted by bruce
Rattling sound?.
I'll pay shipping to get one that rattles. I'd like to autopsy it.

Bruce,

Lance boxed up some wide band cadavers for you. Not sure if there was a rattler in the bunch or not. If not, and you would like to check one out, let me know and I can probably dig one out. We keep a lot of the failed wideband sensors that are returned to us for a checkout.

 

[Craig Smith]

Derrick,

I see two problems. First, if no lambda symbol appears, then the ECU isn't calibrated for that sensor. Second, the UEGOS values you are reporting indicate to me that either the ECU or the wiring has gone bad. Disconnect the intermediate cable between the main harness and the sensor and see if that affects anything. If not, you'll probably want to call the tech line for an RMA and have it looked over. I believe something is broke.

 

[tazgn]

Craig,
Can you tell me which pin-outs from the ECU go to the O2 sensor? This way I can do some continuity checks of the wiring. I suspect this may be the cause as it happened following reinstalling my motor and trans.

Derrick