Thread: Have a SAFC II issue, maybe.

I think I may have an issue but I'm not sure, for some reason my A/F reading will not go to where I want it preferably 12.8-13.0 @ WOT after 2k rpms. No matter how much fuel I add from 2k-3k in 4th gear my reading are in the 14's and 15's then finally it gets down to 12.6-13.0 where the power feels the best.

Is this normal or do I need to make more adjustments somewhere with the afc?

You are probably still in closed loop between 2k-3k, you can't get afr's to go any lower if thats the case, nor do you need to.

So could changing my Hi - Lo Throttle do anything?

It really isn't a big deal but on the highway I would like to see a little more pull when in low rpms. It feels sluggish under 3k, very lean in the 14 15's .

No, won't change anything. The car will always be slow under 3k, lol. Try downshifting.

If you want, pull your primary o2 sensor and the car will alway be in open loop and you can tune the entire rev range. 14-15 is not lean when in closed loop, it is the optimal afr for emissions and mileage.

Originally Posted by misternuts

no, won't change anything. The car will always be slow under 3k, lol. try downshifting.

If you want, pull your primary o2 sensor and the car will alway be in open loop and you can tune the entire rev range. 14-15 is not lean when in closed loop, it is the optimal afr for emissions and mileage.

lol

IF you only have bolt ons, going from 14-15 afrs to 13 how much power do u think u will gain? 2 HP maybe???

Like Karl said, If u want to "feel" more power downshift!! N/A specs pull nice from 4500 rpm and up

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Originally Posted by MisterNuts

No, won't change anything. The car will always be slow under 3k, lol. Try downshifting.

If you want, pull your primary o2 sensor and the car will alway be in open loop and you can tune the entire rev range. 14-15 is not lean when in closed loop, it is the optimal afr for emissions and mileage.

So it just takes some time for the computer to enter open loop under 3k at WOT?

I'm not sure on the exact conditions needed to get into open loop. Justin sent me this screen shot from Osiris showing an afr target map (I assume it is from a stock ecu) showing when the ecu switches over from closed loop (14.7 = closed). Unfortunately I don't know how base fuel schedule relates to actual load. Hope this helps: