right this car dont like starting on petrol it somtimes runs at about 1500 rpm for a while or it idles realy lumpy on petrol or gas i just changed the two oxy sensors and it idled fine for a while. it went on the computer and only showed oxy sensors not performing as well as the guy would have wanted them too it has also had new plugs and leads [lucas] can anyone help

While it was on the puter did he reset the adaptive values ? If your LPG is working too far away from the petrol ecu it wont cope.LPG systems seem to fail in a lean manner rather than rich hence your petrol ecu giving a rich mixture trying to cope with the LPG systems inability to give correct fuelling.

i dont know if this will help. i had same trouble when hot it would not start/run on petrol, fine on gas at all times.
an idiot rip off mechanic told me i needed to change the injectors (and quoted me £164 each for parts only) and if that dont work i was then to change the oxy sensors.
i gave it some thought and took some advice pointing to air flow meter, and it was bad connection at the air flow meter connector, that was it.
i squirted it with electrical switch and contact cleaner and it hasnt happened again, now 9 months on.

no he did not reset the adaptive values i will get him to do it and i will swap the airflow meter from my other one.thanks for the advice