Can heat disable an O2?

[Waco84GN]

In my otherwise well running 84 GN on several passes that I have made using Direct Scan I have noticed a sudden vanishing of my O2 readings. They would be great 850's a little rich but on the safe side. Then all the sudden, the would just stop reading or read some insanely low number. I am running Kenne Bell headers and the O2 is mounted in the up-pipe before the turbo. I have a feeling that my EGT's are too much for the O2. I also have an EGT gauge that would get readings of around 1500-1650.

Anyone had any experience with this? I think turbo6x2 repositioned hers into the downpipe for some reason, but I'm not sure if it was related to heat.

Thanks guys.

 

[Jerryl]

........... EGT gauge that would get readings of around 1500-1650.
................ I think turbo6x2 repositioned hers into the downpipe for some reason, but I'm not sure if it was related to heat.

The temps you posted should not damage the O2. Are you running race gas?

As far as the location of the O2 is concerned. turbo6x2 is one of the best in the business and I am unsure of the reason. From what I have read those who reloacted the O2 did it as a "up pipe flow increase" and/or a convenience issue in allowing the tuner to "get to the O2 easy". Do a search for O2 in downpipe as there are various opinions on the operational effectiveness of the O2 on this.

 

[Lee Thompson]

wire

I would suspect a bad or loose O-2 ground wire. It will be in the batch of grounds under the A-C bracket. A small tan wire.
It will be too hot for the O-2 sensor when the tip burns off, but not @ 1500.
I had a friend burn the tip off an O-2 sensor on an 87 once. Don/t know what his EGT was but the remaining part was Casper white.

 

[Lee Thompson]

new wire

Try this. Make a new ground wire and ground it some where on the eng. Run it inside through the window and piggy back it on to the same tan ground wire at the top of ECM, as a simple test. Best of luck.

 

[bruce]

In my otherwise well running 84 GN on several passes that I have made using Direct Scan I have noticed a sudden vanishing of my O2 readings. They would be great 850's a little rich but on the safe side. Then all the sudden, the would just stop reading or read some insanely low number.

While it's been repeated so many times that you can properly tune with a stock O2, when in fact, that's not always true.
Yes, O2 do have limits to the heat they can work in.
IMO, I'd mount an EGT where the stock O2 goes, and then further downstream mount a heated O2 sensor. On mine, I have the stock O2 down by where the cat converter used to go.

BTW, Bosch sensors seem more prone to that then others.

 

[Waco84GN]

thanks for the replys

Well being in college and 2 hours away and not having any days off to work on my car doesnt really help problem solve all that well. I now have a miss that I have to hunt down , but I havent even began to look at yet. Could be fun plugs wires or god forbid the injector harness (whiich I think is causing the miss). Anyways the o2 will have to wait until I can go home and fix the miss.

Thanks everyone

Jerry Berger