Well it's not bad, but it's not perfect....
The general symptoms are:
Low MPG (2.8/-2.9 miles/litre on LPG)
Hesitation on Petrol at about 3500 rpm on hardish acceleration (seems OK on WOT). No hesitation on Gas (maybe because the LPG is richer?)
I'd had a code showing a sensor fault for the upstream o2 bank1, which I tried to change but I couldn't undo the bloody plug*. So, just in case it was throwing the code because the LPG was running too rich for the ECU to lean it back out I reset the adaptive values and took it for a drive on Petrol only to see what happenned.
Immediately after reseting the adaptive values, the idle went to hell. Nasty and lumpy. It took about 5 minutes to get back to normal. Then I took it for a short drive. It was weak, very weak but it kept running and slowly improved.
Codes: Adaptive values out of range, both banks. Knock sensor (1 time). Strangely, I didn't see any misfires recorded on the misfire screen.
I cleared the codes and did ~35 miles on petrol on back roads and tried to get into every part of the rev range in low, medium and high throttle openings. It started out pretty grim but did settle down to being properly driveable, with the exception of the 2/3 throttle hesitation at 3500-4000 revs. You have two choices at that point, back off and let the 'box change up so you can pull away again at just below kickdown or just floor it and it moves on again.
Finally I parked her up and checked the codes again. This time just the "adaptive values out of range, signal too high" for both banks.
So.. I don't think the 02 sensor is necessarily bad. I've been watching the live output and they both seem to switch between the same ranges (about 0.01 to 1.4). Bank one did take a while to read anything from cold(ish) after the first reset - I don't know if that is enough in itself to require a swap. I have the part if necessary, just need to get it up on a ramp and get medieval on it's ass!
Does anyone have any suggestions? I can get whatever info is required from the Nanocom, I just wish you could tell it to "dump everything" to the SD card from Motronic, but if it does that I haven't found the option. Personally, I'm leaning back towards MAF again.. but I don't know these engines - yet :accept:
*I really suck at this :( I couldn't fit my hands far enough up the gap to get a decent grip on it, and I wasn't strong enough to do it with fingertips.