Wideband or ECU problem?

[turboAWDfanatic]

I'm running a Zetronix Zt-2 with a stock ECU. I had to pull the O2 sensor out to drop the down pipe to work on my transfer case the other day, and since then (after bolting everything back together) I've been experiencing two problems. The first is that if I try to rev the engine shortly after start up, it cuts out and sometimes stalls. Slow revving and actually driving it is okay though. This problem dissapears as soon as the engine starts to warm up.

The other problem (also during warm-up) is that my WB reads 13.2:1 at idle instead of 14.7:1. When I change settings on my AFC it wants to stay at 13.2, in the way that the ECU aims for stoich mixture. After I drive for a little bit it goes to 14:7, and on WOT pulls it reads right where it should and seems consistent with EGT's.

The WB worked perfectly until the other day. While I was working on my transfer case I put the WBO2 sensor in a rubber glove and put placed it out of the way up on a crossmember (still attached to the harness). At one point during my work it fell a small distance and bumped the ground, but not violently. I asked Crock at Zeitronix if I damaged the sensor and this was his response:

"Dropping the O2 sensor may crack the ceramic element. However if the sensor is reading the full AFR range is probably ok."

Like I said, the readings seem right and show a full range once I'm warmed up and driving, so it sounds like the element is okay. FYI, my ECU is stock so it bases closed loop operation off of the narrowband. I didn't touch any other intake/maf/turbo/ecu/fuel/emissions related things during the transfer case work. My car was running fine before this. Any thoughts?

Thanks.

[97GSTAUTO]

Check the harness to make sure it's secure. Just for giggles check your narrow band switching point. Because I think when you change the switching point the richer setting is around 13.4

[turboAWDfanatic]

Yeah, both of those have crossed my mind too. I made sure the sensor was plugged in tight. I haven't booted up the laptop to check the switching point, but the thing is that it goes to 14.7 after a little warm up time. But for the first few minutes it stays at 13.2. I can try to lean it out, but the ECU wants to keep it at "13.2", and if I lean it out enough to display 14.7 the engine starts to sputter like its running way too lean. It seems to me that the WB reading is wrong rather than the car running rich.

I don't know much about the operation of the heater on a WBO2, but it seems to me that the heater might not be working right. The reading is off while the car is cold, but after driving around a bit it reads accurately. Is this a correct assumption?