I Have purchased a 08 BF Wagon, Factory LPG, it goes good and everything, but it uses 21 to 22 L per 100, could anyone tell me how to adjust the gas for better economy, or what faults to look for please ?

You need to take it to someone with a scan tool and check the pids, it may be as simple as an O2sensor signal voltage staying low and the stepper motor is retracting to increase the gas because it thinks it is to lean. If the problem is in the convertor the o2 signal voltage will be high and the stepper motor will be extending trying to make it lean. All good mechanics will have a scan tool, the three most important pids will be o2, map, and timing, will take about twenty minutes to diagnose your problem. On early open loop systems you could make adjustments, not this model fully electronic. My bf light throttle cruise 12 litres per hundred klm

I forgot to add, make sure the guts has not fallen out of your pvc valve, that will create an air leak and run lean, low o2 signal voltage and the stepper motor will be trying to compensate for it, tell tale sign high idle.

Thanks heaps for your reply Rod, I might put in a new 02 sensor, If that doesn't fix it, I will take it for diagnosis , Cheers Ash

Hi again, I just checked the Valve, you got it in a nutshell mate, the guts had fallen out , i got the spring and the valve out with a magnet, so i won't have pull the cover off, will get a new one tomorrow, thanks again....ash

Thanks for your input Rod, I put another pcv valve in, and the fuel has gone down to about 16L per 100 around town for short runs, a lot better than 22 . cheers Ash