ultragauge: DFCO disappeared
 

My ultragauge has always showed 9999 instant mpg for DFCO, but now shows less mpg for coasting in gear than coasting in neutral, for example 150 mpg coasting in gear and 225 mpg coasting in neutral.

The bank 1 O2 sensor goes to 0.000 immediately when coasting in gear. I've not checked the bank 2 O2 sensor yet. Any ideas why instant mpg doesn't show 9999 anymore, and am I still getting DFCO?

I can't tell. Any way to read injector status?

I'd have to suggest it's a software error in the gauge. Reset time :o

Are you using the 8 page gauge? Only the 4 & 6 gauge pages display DFCO consistently on mine.

cause & solution
 

Thanks for the ideas and suggestions. The issue occurs with both 8 and 6 gauges per page. Both of the O2 sensors go to 0.000 immediately when coasting in gear.

The issue occurred after changing Pwr off Retries from 5 to 33, and went away with the setting back on 5. Increasing to 22 brought the issue back, but not as badly.

Raising the force MPG sensor by 5 or 10 points might be a remedy, but I will need to do more testing to make sure and to fine tune the setting.

pwr off retries
 

I think increasing Pwr off Retries simply delays DFCO, instead of getting rid of it, so the choice is a tradeoff. I like to use DFCO more in heavy traffic on the freeway, going up hills, steep downhills, and anywhere that shifting to neutral is not convenient. However, I'm raising the pwr off retries to 25 to give the kill switch another try, which will cost about 7 seconds of DFCO, and hopefully won't make much difference to the average mpg reading.

Changing the force MPG sensor ended up messing with the mpg readout, so I put it back on the original setting.

In my experience, PWR Off Retries has no effect on DFCO detection.