wats up to all my jdm peps.. i have a question??? i just put in a pr4 ecu on my 91 ls and the check engine light turned right on but didnt shut off?? the ecu came off a 95 ls?? can anybody tell me wat can be the problem?? thanks

 

ECU and ABS Codes
https://honda-tech.com/forums/acura-integra-6/ecu-abs-codes-here-978933/

 

a 95 ls came with a p75 ecu. obd1. your 91 would be a pr4. non-obd. they are not interchangeable without a conversion harness and auxiliary wiring. the connectors for an obd1 ecu will physically not fit in a non-obd ecu and vise versa