Contour Enthusiasts Group Archives Forums Modifications Duratec Performance When does the ECU switch from Open to Closed loop?

I'm trying to determine when the ECU (V6 SE MTX) switches from open to closed loop mode. It simply depends on a throttle percentage, correct?

I'm trying to use a combo of a Proflow MAF and an APEX-I SAFC to tune 19lb injectors in a SVT intake on an otherwise normal V6. I figured the new MAF could take care of the closed loop fuel metering, and then have the SAFC take care of the open loop (no feedback) mode for full or almost full throttle settings. Is this feasible? The SAFC alone hasn't been able to resolve the problem of the car coding (usually takes 2 days to a week to throw a CEL (too rich) on one bank) .

TIA

Lose the proflo and go back to 17#ers. My oem maf made it to 300hp before I pegged it. Yours should make it to the 200's easy.

To answer your question the computer usually commands about 60% throttle for WOT. If you can read voltage from the maf it's about 2.3v on a factory maf. As for a proflo, who knows what those guys did.

The PCM switches to closed loop at 120 degrees ECT.

The PCM switches to adaptive control at 140 degrees ECT.