What are my narrowbands telling me?

[sevinn]

I have been noticing this for a while now, but mostly ignored it because I'm tuning my maf in open loop using my wideband, but one of my o2 sensors seems to swing like crazy. What is my b1s1 o2 sensor trying to tell me here...is it a leak or a byproduct of being in open loop for some reason? I need to take a scan with my "normal" tune with dfco, cfco and closed loop enabled. '12 base vette m6 with halltech mf103, ported IM, ported TB, 1-7/8 headers, 3" exhaust and tr6i plugs.

[SultanHassanMasTuning]

if you are running open loop, you need to retune your maf curve.

also if your sensors are not switching as need be check your timing as it could be too advanced, but if you cruising and your Mv (o2's) staying flat

also since you have headers you need to adjust for integrator delay.

[DSteck]

If you're in open loop and a narrowband is switching, it means that bank is hovering around stoich.

[MikeOD]

^^^ what he said.

If you're in open loop and your commanded lambda is 1.0, and you see the narrowbands changing dramatically from high to low, then you're right around 1.0. A small % rich and you'll see the narrowband sensor swing to a pretty high voltage...a small % lean, and you'll see the narrowband drop off quite a bit.

Perfectly normal...it's actually telling you that your narrowbands and wideband agree.

[sevinn]

Thanks very much for your replies, it's a bit of a relief to read that it's normal behavior for when I'm running scans in open loop (it's my intention to run the car in CL on the regular).

My tune is very much a work in progress as I'm still working on the maf curve (this was my second scan since switching to the mf103 from the airaid I had) and haven't even touched VE yet, but I think I got stuck in a place where I'm trying to be too exact with my changes and I'm losing a bit of the polynomial feel to the curve. I need to look into integrator delay as I've never read about that before!



My timing table is mostly stock (I've actually dropped timing in some sectors to try to get rid of some KR I was seeing), but it very well could be too advanced. The help is much appreciated!

[sevinn]

Should I decrease the integrator delay table to adjust or LTs? I can't seem to find a consensus and my assumption is that I would want to decrease the delay since the actual sensor is farther away now.