I have a 97 honda civic converted to a 2000 si i have a swaped ls vtec i need to know what wiring harness i need to buy to make it run right and ecu and if i have to get a new in dash wiring harness. I would rather keep the stock in dash wiring harness.

 

What model civic do you have now? DX, HX, LX, EX?

 

converted to a 2000 si how? front end?

 

Instead of having a mishmash of wires and unreliable car , when doing a swap buy the best you can for the car that way there are no headaches later... or like you are having now.

There are places that make aftermarket harnesses that wont give you headaches.
Rywire.com
Chasebays etc....
I'd lean more toward rywire.

 

Obd2a to obd1 converter whit a p28 ecu