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Thread: Stoich and part throttle AFR

  1. 09-08-2021 #1
    Hammersrt
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    Stoich and part throttle AFR

    I have raised my stoich to try to have a richer idle. When in open loop it shows to work fine but once it goes into closed loop my idle is 14.8 to 15.3. I have installed 2 AEM widebands, one on each bank. I'm not that of a seasoned tuner and wonder what area should I look at to correct this in closed loop? Also I had a software update about 3 weeks ago and I have noticed under the O2 sensors that the front and rear are now missing and no way to enable or disable.....why has this feature been removed??? I have sent messages to HP TUNERS and they keep coming back saying I'm asking for a tune (I'm not asking for a tune) and they talk about keeping the emissions correct.....I guess they are trying to make EPA happy.......they should not remove a feature that was previously there ...be careful on updates
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  2. 09-08-2021 #2
    white1
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    New EPA regulations. Covering their ass
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  3. 09-08-2021 #3
    spoolboy
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    Leave stoich alone unless you are changing to a fuel that requires a different stoich. This will not change the AFR from what the o2 sensors want.

    For what it's worth, the disable buttons didn't work right anyway. It may not be the EPA, but an actual fix to the software.
    If in doubt, multiply everything by 1.1.
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  4. 09-08-2021 #4
    Evo8john
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    The only way you can really lean out the AFR during cruising would be to just lock it in open loop and tune the MAF/VE tables to achieve what you're looking for. Closed loop on the stock ECU will always target stoich.
    Owner/Tuner@Evolution Automotive Performance
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  5. 09-09-2021 #5
    GeForce1986
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    why you even want a richer idle ?
    my car have big cam and it idle about 17 to 20 some times afr .
    and you can control the o2s by temp
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