STFT kicking in in Open Loop??

[stan]

I have been logging on my stock 2010 Camaro trying to make sure I know what I'm doing in preperation for a blower next week. Ran it in closed loop and tweeked on the MAF about 4% from 3000 hz and up. LT and ST fuel trims were just about all 0's now. Hooked up my AEM wb and was doing some logs in what I thought was open loop to make sure it was reading normal. I had unpluged and removed the drivers side front o2 sensor to install my wb. I thought in OL that would be ok. Logged my 10 mile trip home last night and noticed afterward that about 4 min (frame 4153) into the log it had 2.3% STFT on bank 1. It goes back to 0 WOT but then comes back at cruise. I set the CL enable temp and o2 readiness temp to 285. I set the LTFT enable learn temp to 285. DFCO temp enable to 285. COT to disable. I set all 4 OL EQ ratio tables to 1.00. Does that sound correct?? Hopefully someone can tell me what is going on.

thanks
Stan

[5_Liter_Eater]

Did you clear out the fuel trims after disabling closed loop?

[stan]

I thought so. Just wierd that it took so long to show up. This morning it did the same thing after 6 minutes of logging.

[stan]

Cleared the trims several times. Bank 1 still ends up coming up with 1 to 3 % STFT. It doesn't seem to be doing anything I believe?? Both inj banks have the exact same pulsewidth. I even comanded open loop with the VCM controls and it made no difference. If I comanded closed loop it of coarse went nuts and had about 20% trims with the left narrow band O2 sensor missing. Should I worry about this or just ignore it???

[5_Liter_Eater]

That is weird. The tune you posted has everything correct for true open loop. Try reflashing it maybe? Sometimes I forget whether I've flashed a tune I've edited or not.

[stan]

Noticed that whenever the speed goes to 4mph or less the trim is either reduced or goes back to 0.

There is not a problem pulling the stock o2 sensor like I did is there?? I had one vendor tell me I couldn't do that but it didn't make sense that I couldn't in OL.

If it is really triming one bank wouldn't the injector pulse widths be different??

[5_Liter_Eater]

The only problem I could see is it would keep you from being able to do closed loop. In open loop there shouldn't be a problem.

[Higgs Boson]

Do you have the option selected to use stft in open loop?

[stan]

I have seen that field on some LS1's ive tuned but I don't see a field like that on my LS3 unless I'm just missing it. I of coarse have a check engine light on because of the missing o2 sensor. Could that have anything to do with this??? Would unchecking the diagostic codes off the list do anything with this??? It takes several miles before the STFT shows up on the log, could that be the time it takes to run diagnostics??

thanks

[Closer_2001]

Anyone figure this out? I have the same problem in my 09 CTS-V. Refuses to go true OL, driving me insane.

[Gh0st]

Set your 02 readiness parameters to 284. I had this same issue and Bill from HPTuners suggested I do this. Worked like a charm.

[Closer_2001]

I thought I had that handled in my tune, didn't save it correctly.

So, yes I agree - 02 to 284. And, also make sure you also save the file

[Brians6]

Did you clear out the fuel trims after disabling closed loop?

I know this threads old but, what do you mean by clearing out the fuel trims after disabling CL? Do you mean in the scanner?

[Gh0st]

I know this threads old but, what do you mean by clearing out the fuel trims after disabling CL? Do you mean in the scanner?

Yup, with the VCM controls.

[superwagon]

I noticed this on a 07 avalanche I just tuned a couple weeks ago. I think that I ended up forcing open loop in the scanner vcm controls then cleared fuel trims. When I did that it seemed to stay in open loop with no STFT.

[Brians6]

So, if you reset the fuel trims once you allow it to go back into CL what happens? I ask because when i did this my LTFTs were all over the place and im not sure if they were like that before as i did not take a log before dicking around with OL /:

[Gh0st]

Brian, try what I suggested about the 02 Readiness. I give credit to Bill for suggesting that one to me because I couldn't understand why CL kept working even though I turned it "off".

If you allow it to back in to CL, it works just like normal while in CL. If your LTFTs were all over the place then I would imagine your fueling is off Just clear the LTFTs and let them rebuild if you are concerned.

[Brians6]

If your LTFTs were all over the place then I would imagine your fueling is off Just clear the LTFTs and let them rebuild if you are concerned.

Did that last night and thats when i got the irradicate LTFT's however i just took another log this morning on my way to school and they seem to be getting better, i guess it just takes awhile for them to settle and re-learn?
thanks for the help