Hi, i have just sorted this problem using advice from this site and others though some advice read was clear others were not..
To simplify I decided to write my log of events ;; ---
Firstly the pedal test.. Engine off.. press both accelerator and brake to the floor and hold them there, then turn the key till the lights come on the dash (still holding pedals to floor), all the lights will come on as normal then the red spanner symbol will flash the code.. count the flashes.. 1-9 as they are or 10 times for 0.. There is a clear gap between each number and you will end up with a four digit code. write it down and look up on the internet.

If you get the code 0335 thats the crankshaft sensor, they are available on Ebay for massively varying prices.. I got a none bosch one for 10.75 + 1.00p+p (bosch available for 5.00 more. The none bosch has 2 year warranty so no worries there anyway.

Fitting the part I parked the passenger side on the kerb and jacked the drivers side up. (make sure you use an axel stand!).. you need an 8mm spanner if like me you dont have torx spanners or sockets.. theres just one screw securing the sensor which is located to the rear of the engine at the drivers side above the starter motor.. (very fiddly) You could drop the starter to make access easier, I chose not to and managed..

After I finished I started the car and it fired perfect and the pick-up was back to normal. The engine management light which had come on a day or so after the first light (the red spanner) however stayed on. Dont worry, apparently there is a memory in the engine management and it remembers the fault for a while. Mine cancelled itself a couple of hours later. I read you can cancel the memory by turning the ignition on / off ten times or alternatively disconnect the battery for 15 minutes..

I hope this helps someone and saves a bit of time looking at conflicting theories..

Thanks to the individuals who gave the sections of advice I have collected on here..... Andy : )