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Thread: WOT O2 Voltage / AFR Reading Question - Stock L36/L26

  1. #1
    Tuner in Training
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    WOT O2 Voltage / AFR Reading Question - Stock L36/L26

    Forward asking - don't rip me up for checking a WOT tune with a narrowband

    I'm having some KR issues with my wife's DD, an 02 Grand Prix GT w/a stock L36 and HV3 installed. As I've never had any interest to really dial in the WOT tune on this car, as it's just a beater car, I never really did any research to see what a STOCK NA L36/L26 should be running at WOT. I'm sure it would be the same as any stock-ish port-FI Naturally Aspirated vehicle...

    Anyway, the question is, what should I be looking to expect at WOT for this car? Whether it be on O2 narrowband readings or AFR readings?

    Thank you!
    2000 Pontiac Grand Prix GTX T/C
    Current: T62-1, S1X, GMR goodies

    2004 Monte Carlo SS Intimidator
    Current: S1X, 3.5, DD

  2. #2
    Tuning Addict 5FDP's Avatar
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    Base fueling at full throttle should be 12.4 AFR but then there is an adder table that adds to the commanded AFR over time and rpm. So if you canned it for like more than a few seconds the AFR slowly drops from 12.4 to something richer, slowly into the upper 11's.

    Generally speaking, o2 sensors like to show 890-930mv give or take. A super rich setup might show 950+.

    If it's running 87 octane, the knock is to be expected if you ask me. So long as there isn't a background issue like a vacuum/exhaust leak, worn out engine/trans mounts or low fuel pressure.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

  3. #3
    Tuner ZeroBoostBuick's Avatar
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    Stock...
    Probably around .850 on the narrowband.
    13 to 12.7 AFR Command in first gear, then after shifting into second gear, it might go all the way down to 11.6 afr-command. Don't be surprised if you see 6+ degrees of KR on Regular 87 Octane