Would like to know if the problem is still there on petrol -

Leave it on gas and we will interrogate codes and grab sensor behaviour before doing a battery off reset to try a few days on petrol as suggested by John

Rich running not usually a big problem - just like leaving an old fashioned choke out too long - lean is an issue as burns valves and melts pistons

I don't think the trip computer numbers are significantly different - will also depend on this weeks butane/propane proportions in LPG etc etc and if the LPG ECU is set differently as trip computer is from petrol ECU

In the end it is tank to tank manual calculations the have real meaning

Good morning all, especially to Terry and John!

So the ACT dealer responded and advised me to get a quote, and to ask the LPG specialist for a retune afterwards.

Just spoke to the service advisor that Terry recommended, and he is convinced that, instead of two faulty oxygen sensors, I may have one faulty oxygen sensor (I think he is referring to the pre-cat one on the firewall side...the blue line in the middle graph), and one catalytic converter...?

(This is despite me advising him that the post-cat green line in the middle graph does respond with more throttle input, as with the pre-cat blue line but that is moving less than ideal, and the bottom graph is exactly how Terry's daughter's Outlander behaves...he is saying that, perhaps at least in the 380, the green line should not move much at all...?)

[Perhaps Terry will need to Reply All to this service advisor in our emails so far, with the part of the graph where we were using petrol, and where I was pumping the accelerator pedal whilst on LPG. This may prove that the post-cat green lines ARE supposed to move up and down also, just in a lower frequency than the pre-cat sensors...?]

So now to have it diagnosed by the service advisor and his team, would cost $145. I am not sure if the ACT dealer likes the sound of this, but I will have to let him know regardless. In any case, I have a feeling I will have to cop this charge myself for now, just to get the ball rolling...

At least things are heading in the right direction I guess!

Thank you very much Terry for sending the complete graph to John (the service advisor), and explaining how the sensors are behaving under the different conditions we have presented (running on LPG, running on petrol, and pumping the accelerator whilst running on LPG). Please send the screenshots as a separate attachment as you did before, rather than in line with the email text as I did...because he was then unable to zoom in to view in more detail...silly me!

John (the Administrator): the car was purchased early in June, so by now it is just out of the standard 3-month warranty. But because it stalled in a motorway tunnel on day one (and again in a car park, plus a milder symptom of the delayed then surged acceleration, which means the engine may already have been running lean at the time, if not before! More about this later...), and since the first repair, it has started misfiring (still within the warranty), the dealer is obliged to fix it. But it does not stop the dealer from going for a short term fix, which is why I am requesting the work be done properly in a Mitsubishi service centre that has experience dealing with dual fuel 380s. Let's see what the dealer says this time...

Regarding the engine, I am just concerned that the prolonged lean running (at least on Bank 1 based on the graphs) would have already caused enough damage that cannot be seen/detected unless the engine is pulled apart. As you've said, these oxygen sensors are not supposed to last beyond 100,000km, and the car has now done in excess of 147,000km, so it may have been running lean for almost 50,000km, if not more. Curiously, none of this was picked up by the pre-purchase inspection report I've purchased prior to purchasing the vehicle. Tried asking the inspecting company about their 30-day warranty (http://www.vehicleinspectors.com.au/Conditions/) immediately after the motorway stall and what they can do about this, and asked again recently, but no joy from them either...

Hopefully the dealer will just approve a once-and-for-all fix at Terry's recommended repairer, and it will work out fine. But yes, I am still concerned about the prolonged lean running, and how much damage it may already have caused the engine. A replacement engine from eBay and/or the wreckers? Hmm...

It was SO much easier when I bought a (then) 4-year-old and supposedly unreliable Astra Turbo with 104,000km and a full exhaust from the dump pipe onwards, back in 2007, and that was with a mere NRMA inspection report. That car has now done almost 175,000km, and besides regular servicing, wear and tear and despite more mild modifications, still running great with no sign of needing a new clutch yet (indeed, the friction point is pretty much still at the same amount of clutch pedal travel, and it still clamps fine)! And now so much more trouble with this particular 380 with supposedly a far more detailed inspection report...? Quite sad and incredible, really! *sigh*

Really hope the 380 is fixed properly so I can keep it, though, as it definitely has a far broader range of talents/capabilities than my more narrowly-focused modified Astra!