That’s my point, the LPG can still cause problems even if you’re not using it.

I'm no diagnostics wizard but with fuel trims at max it seems to point to over fuelling/flooding almost if you like So once again pointing back to the MAF or big air intake somewhere. only a suggestion look on the tube for testing maf sensor and see if you can test /rule out this is not the problem it's where I'd start. You say it was replaced did it come from a reputable company as there are so cheap copies around of stuff. also is there a tap/valve on the lpg tank so you can isolate supply the engine. Range rover 4.2 SC 06MY.

Good news - smoke test came back showing the bung had been left off the pcv! Guessing that could cause some issues! Is there more than one place the bing could go though as I watched the guy put it on unless he didn’t push hard enough - wondered if he could put in wrong place? Also nozzle for c8 gas was loose so will cover in gasket seal and tighten her up.

Now that’s sorted (hopefully)

Here she is idling - does this just sound like the standard vanos rattle to you firstly? Secondly in the background there is another noise no idea the source of it but it sounds like a resonating? Any thoughts? Cheers all
 Current stable:
2006 BMW M6
2007 4.2 V8 S/C FF
Gone:
2002 4.4 V8 FF

Hey, did you get a resolution on this? My 2004 M62 on dual fuel has the same / similar issue and has the mechanics stumped.
If I'm running on LPG at the end of my run, then the next morning when its cold, starting on petrol, it starts to run like a dog after about 10 seconds of idling with engine light flashing, codes indicate misfires in multiple cyls. It was a lot worse earlier on with stalling immediately after starting (maybe 3 or 4 times at its worst) then seemed to rectify itself over time, have no idea how.
However if I switch to petrol maybe 5 minutes before I stop my run for the day, the next morning is virtually trouble free.
dragging in air I thought had merrit, how would I check for this??. A leaking LPG injector on startup also was a possibility, but had that checked and discounted as the lock off valve doesn't open till later on when she's warmer.
I've got a mate with a decent OBD II tool. its locked to his VIN but does show certain things on my car. I'll try it.

Thanx Matt Once you've driven a Range Rover, everything else seems 2nd rate.. Eeeek I'm trapped for life.

1986 RRC Highline with offroad mods. Arctic Silver
2001 P38 HSE. Ardeness Green.
1995 RRC soft dash (beautiful car) Green.
2005 L322 HSE V8. - Current, most awesome car yet. And most expensive.

Mine was the pcv and the pcv bung and the the maf iirc...

Check the maf fort - on the m62 you can just disconnect it if it runs tons better they would be my first port of call Current stable:
2006 BMW M6
2007 4.2 V8 S/C FF
Gone:
2002 4.4 V8 FF