I am looking for information concerning the Gas Mass Sensor GM Part number 52369145 for a 2002 Chevrolet Cavalier/CNG. I am in need of replacement electronic circuit boards. Can someone please assist me in verifying the correct part number. Visiting the GM Parts web site for part number 52369145 I see a listing for this part number at a cost of $1552.88 plus a $341.63 shipping and handling fee. I have no manual so the only reference information that I have is from prior posts in this CNG Chat forum.
Because of the steep price for this item, I would appreciate any information anyone can supply as to the OEM manufacturer or possible source of supply for the whole Gas Mass Sensor or just the electronic circuit boards through another source other then GM Parts.

Thank you very much for your time and assistance.