dwb87

iTrader: (22)

So, earlier I drove my car. I didn't notice that I was at 1/8th of a tank of fuel until a mile away from home. The only way I noticed was through my narrow band. (I understand that narrow bands aren't a completely reliable source for AFR's.) The narrow band went from 14.1 to 20 and stuck there, until I slowed down. This was on some hills... My question is; If the fuel was low and sloshing around in the tank, possibly not being sucked through the sock filter, would this cause this sort of AFR reading? I drove home immediately. I plan to get gas tomorrow and check this for sure.

K-Tune

iTrader: (26)

Did the car run differently? An actual afr of 20 would barely run. You shouldn't run your car with less than 1/4 of a tank, being submerged helps the pump stay cool and prolong it's life.

dwb87

iTrader: (22)

I really should have checked the gauge before I even left my house. The car didn't run differently at all when I saw the 20.0 AFR. I'm hoping it was just the lack of fuel, and/or an AFR misreading by the narrow band.

sharingan 19

iTrader: (16)

Its more likely that your O2 sensor is taking a **** than anything else. As stated, your car wouldn't run@ 20 afr, (that's the type of reading you see coasting w/your foot off the gas). Plus most narrowbands don't even read that lean anyway.

dwb87

iTrader: (22)

****... What is the life expectancy for O2 sensors on RX-7's? It seems like people go through them like crazy.

arghx

iTrader: (3)

With a stock gas tank a very low fuel level can definitely cause a lean mixture due to fuel pressure loss. I've had it happen to me many times. However normally that's under WOT operation on a modified boosted engine, because the torque makes the fuel slosh in the tank.

At low loads I suppose it could happen but it seems much less likely. A stock o2 sensor is a simple 1 wire unit that you can get at Autozone for $30.