Many thanks for your replies peeps!
Right, after a massive bust up with the mrs about how much I was spending on the car
I sat up and wrote a methodical list as to what could be causing the problems. I reset the throttle etc that night via that procedure.
The next morning I drove like an old dear to my mates garage, (clocking a massive 49MPG, not bad going!) with the list. Spoke to Dan at Auto Lusso, Cheers guys! (Not sure if its the same place as you Autolussosouth, but Nice one anyway! Many Thanks for your reply!) Scanned the ECU and it came back with only 2 faults, as follows:
Injector Fault cylinder 4 low voltage
Misfire cylinder 4
misfire cylinder 1 had disappeared,
We cleared the faults, started her up and still a miss!
So some head scratching was done and Nick, charlie and myself set about making it a mission to find the fault. Anyway, we cleaned the MAF again, contact cleaned ALL plugs and sockets that were physically possible the get to and started checking both looms for the coils and the injectors.
Low and behold, started finding breaks in the insulation on the Injector loom, obviously a previous problem that a yip yip coyote garage couldn't detect or problem solve, so they decided to hack away at the wiring loom!
We started repairing the wiring loom where they'd broken it by cutting off the old wires that were damaged and soldering them back together, not the done thing but it was the only choice at the time. Then we got to the plug for injector 4, we all cringed as soon as we saw it! The female connectors on the plug were oval (meant to be rectangular!). Some idiot must have been stuffing probes down there to check continuity through the loom, which would also explain why there were breaks in the insulation.
So after laboriously trying to rectify the plug to make a good connection we started putting it all back together. I must admit, I felt pretty negative given the problems I'd had.
We sorted and cable managed all of the loom and started her up! And voila! A purring JTS! revving, idling and sounding sweet!
And to top it off, I'm easily doing 38MPG with a heavy foot, to and from work which is apparently almost impossible. I think she just needs to be looked after and has possibly been worked on by a complete moron in the past.
Many thanks to everyone that replied to the threads i posted and also Auto Lusso for the recon injectors and also the helping hand along the way, top job!