ZD 30 Series 1-3 #22680AD21A (previously 22680AD210 which was before that 22680 AD201)
ZD30 Series 4 #22680 7S000
Last I knew these were the correct part numbers. Try emailing
www.nizzbits.com.au to see if there is a newer part number.
I would suggest getting a code test done before you replace anything else.
Tony