Just got my car back from the dealer ($310 later) and was told my car was throwing a knock sensor code brought the car back several times and the end result was I need a prom which is obsolete I have a 1990 Camaro RS 305 H.O with a 5-speed...what can I do?

 

start searching. you will want the part number/letters off the prom inside the memcal. is it the prom or memcal. heres a memcal.
1985-1992 Chevy Camaro TPI Computer Chip 305 V8 Auto | eBay

also found this for the 90

01 16163137 EPROM,ECM
With RPO 5-SPD M/TRANS(M39) CODE 9513NJH,5661ATNW,2500ASNH,9487ANJR,6208AWLS,3157AX YB

01 16163138 EPROM,ECM
With RPO 5-SPD M/TRANS(MK6) CODE 5668ATNX,5504AWFZ,9483ANJS,9508ANJJ,3160AXYC

 

Thank you for your informarion, I found a prom and an updated knock sensor...really appreciate your time.