Nexus Plug-in ECU - Honda EP3 (01-05) DC5 (02-04) HT-231001

Plugs directly into the factory Honda harness and mounts in the stock ECU location — no wire-in harness, no adapter, no pinning. Fits the 01-05 EP3 Civic Si and the 02-04 Integra Type R / Acura RSX.

For a K-series this is the cleanest path off a stock ECU that exists. Factory functions stay intact, and the auxiliary connector adds drive-by-wire throttle, O2 control, flex fuel, and oil and fuel pressure sensing — so an E85 conversion or a base-map-to-boost build doesn't need a second controller for any of it.

Race side: CO2 boost control, race timer, advanced torque management, launch control, nitrous control, and 128 MB of onboard logging. Setup runs through the NSP wizard or the Haltech Connect app, and built-in Wi-Fi means you can datalog and adjust from a phone at the track instead of a laptop on the passenger seat.

Includes the ECU, air temp and wideband expansion harness with spare pins, air temp sensor, mounting hardware, vacuum hose and T-piece, USB cable, and quick start guide.