today's O2/FTC/Idle AFR stupid question
04-14-2006, 09:27 AM
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today's O2/FTC/Idle AFR stupid question OK, thought I'd start the morning out by asking yet another stupid O2/FTC related question.
At startup (warm) I'm in FTC 20 and O2s switch fine. Approx 1min 40seconds after startup car moves to FTC19 and no more O2 switching from then on...well at least at idle. Any thoughts/ideas on the switching, or why the change from 20 to 19 (FTC) makes a difference??
At startup (warm) I'm in FTC 20 and O2s switch fine. Approx 1min 40seconds after startup car moves to FTC19 and no more O2 switching from then on...well at least at idle. Any thoughts/ideas on the switching, or why the change from 20 to 19 (FTC) makes a difference??
04-14-2006, 09:30 AM
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If the O2's don't switch, that usually means they're bad.
According to the Fuel Trim Cell discussion linked in Horist's sticky, FTC 20 is open loop idle (before your car warms up) and FTC 19 is closed loop in gear idle.
Only thing I'd say is your O2's are probably bad.
According to the Fuel Trim Cell discussion linked in Horist's sticky, FTC 20 is open loop idle (before your car warms up) and FTC 19 is closed loop in gear idle.
Only thing I'd say is your O2's are probably bad.
04-14-2006, 09:57 AM
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Thanks for the input. I'm pretty sure (99%) that I'm in closed loop when this happens.
I sat in my driveway last night and did about 15 idle scans. I'm logging the Closed Loop Fuel, trim learn and O2 status bits, in addition to O2 output. On a warm start it takes about 5 seconds for the status bits to report everything ready and closed loop operation taking place.
During FTC 20 O2s switch fine. While driving they switch good at steady state cruise. Basically it's when idling in FTC 19 that they hang high. I've moved proportional fueling from 0 to 150 (and various points in between) to get them to swing.....nadda.
I sat in my driveway last night and did about 15 idle scans. I'm logging the Closed Loop Fuel, trim learn and O2 status bits, in addition to O2 output. On a warm start it takes about 5 seconds for the status bits to report everything ready and closed loop operation taking place.
During FTC 20 O2s switch fine. While driving they switch good at steady state cruise. Basically it's when idling in FTC 19 that they hang high. I've moved proportional fueling from 0 to 150 (and various points in between) to get them to swing.....nadda.