What should 02's look like at idle and cruise

[ArthurJGuy]

Does anyone have a scan that they can post up with 02's working correctly, preferably with longtube headers.

My car is an 05 GTO with Pacesetter longtubes.

My 02's seem to be very stable for a few minutes, then it looks like a 9.5 earthquake rolled through. I'm trying to find out what is normal so that I can figure out why this is happening.

[MikeOD]

What you're seeing is normal at warmed idle and cruise. When the car is first started, they will be stable while it is in open loop. Once the car warms up enough to go to closed loop, the O2 sensors will oscillate high and low, it's how the PCM maintains AFR at stoich. When you're at full throttle you should see them go to a high voltage again, but you really can't pick a specific number because they're not really the right sensor to monitor full throttle.

What you really want to look at is not your O2's but your fuel trims...if they're split from each other, or very large percentages...then you either need tuning, or possible have some older worn out O2 sensors.

[ArthurJGuy]

I have closed loop and all fuel trims disabled for tuning, and the 02 sensors are a week old...

If them occilating is normal cool, but should they read similar? There are times one will be reading 700-800mv and one less than 90mv.

[Asylumwarp]

No, they will be different as the banks are different. Thats normal.

[Xjas]

This is mine at idle, not sure if its normal behaviour or not but it seem to run ok.

[Xjas]

And here are couple of highway cruise logs, one is low load cruise, the other is high load cruise, my car runs good so I think they are normal.

[Monaro 383]

Here's a log of my VE ute i took today!!

[aknovaman]

Normal imo.

[IDRIVEAG8GT]

Yep all looking pretty good. You should see the STFT logs I get with Injector Dynamics 1,000's. I had to disable the front O2 codes for "insufficient oscillation" because the injectors react so fast. :P