Plug the conversion harness C101 (large flat grey) connector into your 02-04 style engine harness near the ECU plugs. 

Plug the conversion harness 'E' (white) connector into your KPro ECU.

Secure the relay out of the way near the ECU.

Route the oxygen/air-fuel sensor connector through the firewall to your air-fuel sensor on your exhaust manifold or header.  Extra length is provided on the 4-pin oxygen/air-fuel sensor connector harness so that you can route this in any way desired through the firewall.

Plug the 22-pin green connector into the green 22-pin connector on your dash harness.  This is the connector that originally plugged into your Civic's engine harness.  The green pigtail at this connector is not used on the 99-00 Civic application, so this can be left not connected to anything.

Route the remaining long portion of the harness under your dash to the driver's side.  You can either route it through the firewall on the drivers's side to your driver's side shock tower, or, pull your chassis harness on the shock tower back into the cabin and connect it there. 

The loose yellow/green wire at this connector should be routed to your K series engine's 1-pin temperature switch.  This is used for the temperature gauge on your dash.

The remaining loose wires/pigtails on the passenger side area of the harness need to be spliced into your factory Civic harness as follows:

• blue - tach wire - connect to A19 at the factory Civic ECU connectors
• green/yellow - fuel pump - connect to A16 at the factory Civic ECU connectors
• green/orange - check engine light - connect to A18 at the factory Civic ECU connectors
• green/red - ELD - connect to A30 at the factory Civic ECU connectors
• white/black - brake switch - connect to A32 at the factory Civic ECU connectors