My first Volvo and she's a Little Bit Poorly

[marvintherobot]

Hello Every body, (this is my first go at this.)

I have a purchased a volvo for the first time and i'm trying to sort out a number of issues with it.
The car was already converted to lpg by a company called Prestige LPG Ltd Birmingham and I have no idea what kind of system was fitted.

I have already purchase a Vida Dice and successfully installed the software so I have diagnostics.

The car will drive as it should and the next day it drives very poorly stutters no power flat as a f*rt then picks up when I manually flick to petrol it picks up but it's still not quite as it should (a bit lacking in power)

So my next thing is to start checking ignition.
What spark plugs would you recommend? I have read that single core copper plugs are suggested in other peoples request for volvo perfection (Denso K20PR-U to name one type)

Many thanks

These are the things I have done so far:
Cleaned Throttle body and replaced the gasket
Checked the DIM for any faults (none found)
Cleaned the Maf

Fault code list:
ECM-0040 I know about this one
ECM-120C ECM-1210 ECM-212C ECM-213C ECM-216C ECM-217C
ECM-310C ECM-324C ECM-325C ECM-326C TCM-0350 WTF!!! BCM-007

Car Details:
Volvo XC90 2005 2.9L Engine B6294T Automatic gearbox Converted to LPG
Approx 103,000 miles Spark plugs fitted Bosch FR7DPP+