K-Swap Your 1999-2000 Civic Without the Wiring Headache
Doing a K20 or K24 swap into a 1999-2000 Honda Civic EK? This Rywire Plug & Play Harness package gives you the wiring needed to connect your K-Series engine to your Civic chassis without spending hours modifying a factory harness or trying to figure out wiring diagrams.
Built around the 2002-2004 Acura RSX K-Series electronics, this harness is designed to make your K-swap cleaner, easier, and more reliable.
Whether you're building a street-driven K20 Civic, K24 all-motor setup, turbo K-Series, or dedicated race car, this is the wiring solution that gets you closer to turning the key and getting the car running.
Why Use a Rywire K-Swap Harness?
The wiring is one of the most frustrating parts of a K-Series swap.
You can have the engine mounted, transmission installed, fuel system finished, and ECU ready—but the car isn't going anywhere until everything communicates correctly.
This harness eliminates much of that guesswork.
You get a purpose-built harness designed around the K-Series engine and the 1999-2000 Civic chassis, giving you a much cleaner installation than modifying an old factory harness.
Designed For
Chassis:
1999 Honda Civic
2000 Honda Civic
EK Civic LX
EK Civic HX
EK Civic EX
EK Civic Si
Engine Applications:
K20
K20A
K20A2
K24
K24A
Compatible K20/K24 hybrid combinations using the appropriate 2002-2004 RSX-style electronics
Works With Popular Standalone & Flash-Based ECUs
This harness can be used as the foundation for builds running popular engine-management systems including:
Hondata KPro
KTuner
Haltech
FuelTech
ECU compatibility depends on your specific ECU, engine configuration, and wiring requirements.
Engine Harness Connections
The harness provides connections for the critical K-Series engine components, including:
VTEC solenoid
VTC
Oil pressure sending unit
2002-2004 K20-style crank position sensor (CKP)
Ignition coils 1-4
Exhaust cam position sensor (CPS)
Intake-side top dead center sensor (TDC)
2002-2004 K20-style engine coolant temperature sensor (ECT)
2002-2004 K20-style knock sensor
Intake air temperature sensor (IAT)
2002-2004 K20-style alternator
Manifold absolute pressure sensor (MAP)
Throttle position sensor (TPS)
Idle air control motor
Electronic vehicle speed sensor (VSS)
Fuel injectors 1-4
Coolant temperature sender for the factory gauge cluster
Chassis & Transmission Connections
The harness also integrates important chassis and transmission functions, including:
Reverse lights
Reverse lockout solenoid
Starter signal
ECU connectors A and B
Power distribution connection
Ground connection
Two additional wires for expansion
Charge harness
Important VSS Requirement
This setup uses the 2002-2004 RSX-style vehicle speed sensor located closest to the firewall.
Make sure your engine/transmission combination uses the correct compatible speed sensor before ordering.
Cleaner Wiring. Faster Installation. Less Guesswork.
A K-swap already requires enough fabrication, parts selection, and troubleshooting.
Your engine harness shouldn't make the project harder.
The Rywire K20/K24 Plug & Play Engine and Chassis Harness gives your 1999-2000 Civic a purpose-built wiring solution designed around the components commonly used in a proper K-Series swap.
Instead of spending hours cutting, extending, repinning, and troubleshooting an old factory harness, start with wiring designed for the swap.
Perfect For
K20/K24 street builds, all-motor setups, turbo K-Series Civics, drag cars, road-race builds, and complete EK restoration projects where clean and reliable wiring matters.
Before Ordering
Please verify your Civic year, engine, transmission, ECU, sensors, and K-Series electronics before purchasing.
This harness is specifically intended for 1999-2000 Honda Civic EK chassis using compatible 2002-2004 RSX-style K-Series electronics.
Get the wiring right the first time—and spend your time finishing the car instead of chasing electrical problems.
