i ve had the same issues since fitting the HFC s and i ve fitted the spacers as well.touch wood,since last time after Keyser cleared the memory and i filled up on 99ron fuel it has not come back on.sods law it will now
they do them lightly smoked in the that style, saw them on ebay.com
i used these.......http://www.ebay.co.uk/itm/Nissan-350Z-S ... 336771a647
came from the state in double quick time as well
hope this helps.