Leonardo intermittent error

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Joined:Wed Aug 21, 2013 3:05 pm
LPG System:Leonardo
Car:Jeep GC 4.0
Leonardo intermittent error

Post by shadycat » Mon Sep 09, 2013 8:55 pm

Hi all, I have an 1997 4.0L Jeep with the old Leonardo LPG system fitted that is intermittently coming up with an error. I noticed this recently when the amber light started flashing slowly on the switch box indicating something was wrong. I duly bought the cable and software to hook up the laptop which showed the O2 sensor sticking in the middle-ish or flicking between 0.4-0.6 and on the diagnosis page are the "O2 Sensor inoperative" error and sometimes accompanied by "O2 Sensor lean too long" error. When this happens, the actuator also climbs horrendously up to the max it is allowed and the whole thing suddenly stinks of burnt/unburnt gas. I obviously thought that this was only due to a faulty O2 sensor but the odd thing is that if I switch off, pull the fuse on the Leo, or disconnect the battery and put it back, then fire it up, the O2 errors are gone and the sensor works fine again flicking back and forth from 0.1-0.9 and the actuator running near default at idle and beyond. This will stay like this for a few hours of driving, then without warning, the situation returns, usually preceded by the tank level display suddenly showing half of what is in there (4 lights suddenly become 2 etc) and the familiar smell of gas.

Any ideas what could cause this? If it were a faulty O2 sensor, surely it wouldn't suddenly work just by resetting the Leo? I have cleaned the iac to no avail and all else seems ok, occasionally though it runs badly even on petrol, but I cleaned the MAP sensor out and that, for the time being, seems to have helped the petrol situation, but that was also intermittent.

Is this just an O2 sensor failing? Can it really be that simple? Any help would be greatly appreciated.

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