Ressurecting this old thread. Turns out the pinking was down to the MAF, thanks Wammers.
Swapped it out for another cheap pattern one to confirm and the pinking went away, for about a fortnight, then started throwing the same code again. Have ordered the Bosch MAF now.
My question is will I need to have the fuel trims reset in order to gain the optimum fuelling from the proper Bosch MAF?