Low load tuning with stock O2?

[376FD]

I have a '93 RX7 with a L92 from a '07 escalade and a T56 manual trans and the car runs/drives pretty darn well. I've gotten high load A/F sorted on a dyno, with the wideband in the tail pipe, but it has a slight stumble at 1700rpm and light throttle and the LTFTs are all over the place at low rpm. I cruise in the 1500-1800 rpm range so this gets annoying. I have a wideband but no bung in the exhaust for it.

My question is this: am I okay to tune the part throttle stuff with the stock O2 sensors or should I pull a stock sensor out and put the wideband in there? Or, option three, just suck it up and get a bung welded in for the wideband sensor? This is all very light load stuff, just cruising around on city streets or at "slower" freeway speeds. Thanks for the help!

[Gh0st]

There's no reason you can't try using STFT(as long as your narrowbands are working well) while in open loop MAF and then SD to try and get your non-WOT air fuel situated.

Wideband is the preferred method though.

Is the engine stock or do you have something done to it?

[376FD]

The engine is stock internally, I swapped to a LS3 intake and injectors and am running a credit card style maf as well. Other than that I just have a free flowing intake, long tubes and full exhaust.

[5_Liter_Eater]

I do all my part throttle tuning with the narrow bands/fuel trims. I do both at the same time with a filter. One histo plots STFTs (LTFTs disabled) against the VE table (or MAF if you're running a MAF tune) while commanded AFR (sens.121) is > 14 and another histo plots AFR Error against the same table when sens.121<14. Just have to be sure not to overlap when you're making corrections.

[376FD]

Thanks for the replies guys, I've been logging my trips to work (~6miles) and then doing a little playing at night. Unfortunately I don't have a lot of time but I seem to be working in the right direction. I'll just keep making small changes. The car already seems to drive smoother. I think smoothing out my spark tables helped that too. I'm in no rush and I know it's a bit of a process.