PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

How far will a computer correct afr?

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Old Feb 11, 2004 | 10:36 PM
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Default How far will a computer correct afr?

Just as the post say's. How close do you have to tune before the computer tunes it's self.
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Old Feb 12, 2004 | 08:06 AM
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If it has to pull the tune by more than 25% (+ or -)
in closed-loop operation you will set a code MAF code.
I believe that's the limit of the trims' "pull range". The
PCM only "tunes itself" in the part-throttle, closed-loop
regions.

Running that far off still leaves you with poor WOT
performance and transient-throttle behavior, maybe
worse things if you err on the lean side (on the rich
side, it's just a pig).
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Old Feb 12, 2004 | 09:47 AM
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In closed loop operation with the O2 sensor hooked up your car will only correct the a/f ratio between 13.0 a/f and 16.6 a/f.

If you car strays outside the above said boundries in closed loop you will set a DTC. The car will still attempt to correct itself, but it will apply its maximum correction of 1.7 a/f points.
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Old Feb 12, 2004 | 12:40 PM
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I have some logs that show +/-50 strims
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