Haltech Nexus S2 Plug-and-Play ECU – OBD1 Honda Civic / Integra

Modern Standalone Engine Management for Your OBD1 Honda

Still running an old chipped P28, P72, or other factory OBD1 ECU?

The Haltech Nexus S2 Plug-and-Play ECU Kit gives your Honda a modern standalone engine management system without requiring you to completely rewire the car.

Designed for compatible OBD1 Honda B-Series applications, the Nexus S2 connects to the factory engine harness using Haltech's plug-and-play adapter and gives you far more control, datalogging, safety strategies, and expansion capability than a traditional chipped ECU.

This is an excellent upgrade for serious:

• Naturally Aspirated Builds

• Turbo B-Series Builds

• Supercharged Builds

• Street Cars

• Drag Cars

• Road Race Cars

• High-Horsepower Honda Builds

Supported Vehicles

The Haltech Nexus S2 OBD1 Honda Plug-and-Play kit is designed for compatible manual-transmission Honda/Acura applications using the factory OBD1 B-Series engine harness, including:

Honda Civic

• 1992-1995 Honda Civic

• OBD1 B-Series applications

• Manual Transmission Only

Acura Integra

• 1992-1995 Acura Integra

• OBD1 B-Series applications

• Manual Transmission Only

Honda Prelude

• Compatible 1992-1995 OBD1 B-Series applications

• Manual Transmission Only

Honda Accord

• Compatible 1990-1995 B-Series applications

• Manual Transmission Only

Important

This specific Plug-and-Play kit is designed around the Honda OBD1 B-Series ECU connector and wiring configuration.

If your vehicle is using a custom swap harness, K-Series conversion, H-Series conversion, or modified OBD1 wiring, contact us before purchasing so we can verify compatibility.

What Comes With the Plug-and-Play Kit

The complete Haltech Honda OBD1 kit includes:

• Haltech Nexus S2 ECU

• Honda OBD1 Plug-and-Play Adapter Harness

• M14 x 1.5 Intake Air Temperature Sensor

• Matching Air Temperature Sensor Connector and Pins

• Auxiliary 16-Pin I/O Connector and Pins

• USB-C Communication

• Startup Support from Kugan Tuning

The adapter connects the Nexus S2 directly to the factory Honda ECU connectors, allowing you to move to a modern standalone ECU without building an entirely new engine harness.

Why Upgrade From a P28 / Chipped ECU?

The classic Honda OBD1 ECU has powered fast Hondas for decades.

But modern builds often demand more.

With the Nexus S2, you gain access to features that simply were not part of the original Honda ECU architecture.

Instead of working around the limitations of a 30-year-old ECU, you gain modern control over:

• Fuel

• Ignition Timing

• Boost

• Flex Fuel

• Drive-By-Wire

• Knock Control

• Launch Control

• Traction Control

• Engine Protection

• Datalogging

• CAN Devices

• Additional Sensors

• Advanced Motorsport Strategies

This makes the Nexus S2 ideal for builds where reliability, safety, and expandability matter just as much as horsepower.

Built-In Wideband Controller

The Nexus S2 includes an onboard wideband O2 controller.

It supports:

• Bosch LSU 4.9

• NTK Wideband Sensors

This allows the ECU to monitor air/fuel ratio directly without requiring a separate standalone wideband controller for the primary sensor.

Wideband data can then be used for:

• Closed-Loop Fuel Correction

• Datalogging

• Tuning

• Fuel Learning

• Engine Protection

• Lean Condition Protection

Additional wideband channels can also be added through compatible Haltech CAN devices.

Built-In 4-Bar MAP Sensor

The Nexus S2 includes an internal 4-bar MAP sensor.

This makes it suitable for naturally aspirated and high-boost combinations without needing a separate external MAP sensor for many applications.

Perfect for:

• Stock B-Series

• Naturally Aspirated Builds

• Turbo B-Series

• High-Boost Applications

• Speed Density Tuning

Advanced Boost Control

For turbocharged builds, the Nexus S2 provides powerful boost-control strategies.

Features include:

• 4D Closed-Loop Boost Control

• Boost by Gear

• Boost by Vehicle Speed

• Boost by Throttle Position

• Boost by Race Timer

• Multiple Boost Corrections

• Rolling Anti-Lag

• CO2 Boost Control Capability

This allows your tuner to control power delivery based on how the vehicle is actually being used.

Instead of simply targeting one boost pressure everywhere, boost can be managed by gear, speed, traction, and other conditions.

Flex Fuel Ready

Running gasoline and E85?

The Nexus S2 supports full Flex Fuel tuning.

Your calibration can automatically adjust based on ethanol content, including:

• Fueling

• Ignition Timing

• Boost Targets

• Cold Start Enrichment

• Engine Protection

• Other User-Defined Strategies

No need to manually switch tunes every time the ethanol percentage changes.

Advanced Engine Protection

One of the biggest reasons to upgrade to a modern standalone ECU is engine protection.

The Nexus S2 allows your tuner to create multi-level protection strategies using sensors such as:

• Fuel Pressure

• Oil Pressure

• Coolant Temperature

• Intake Air Temperature

• Wideband AFR

• Boost Pressure

• Exhaust Backpressure

• Knock Sensors

• Ethanol Content

• Additional Analog Sensors

If something goes wrong, the ECU can be configured to take action.

Depending on the strategy, this can include:

• Reduce Boost

• Limit RPM

• Reduce Throttle

• Add Fuel

• Remove Timing

• Trigger Warning Outputs

• Enter Limp Mode

• Shut the Engine Down

For high-horsepower Honda builds, this level of protection can be extremely valuable.

Knock Control

The Nexus S2 includes dual knock inputs with engine-position-synchronized knock control.

This gives your tuner another tool for monitoring combustion and protecting the engine under load.

Properly configured knock control can be used alongside:

• Wideband AFR

• Fuel Pressure

• Boost Pressure

• Intake Temperature

• Ignition Timing

to build a much more complete engine protection strategy.

Drive-By-Wire Support

Planning to convert your Honda to electronic throttle?

The Nexus S2 supports dual drive-by-wire throttle control.

This opens the door to:

• Modern DBW Throttle Bodies

• Throttle Mapping

• Traction Control

• Launch Strategies

• Torque Management

• Improved Idle Control

• Additional Motorsport Functions

This is especially useful on custom or modernized Honda builds.

Motorsport Features

The Nexus S2 includes advanced motorsport functionality such as:

• Launch Control

• Rolling Anti-Lag

• Anti-Lag / Rotational Idle

• Flat Shift

• Traction Control

• Transbrake Control

• Race Timer Functions

• Nitrous Control

• Boost by Gear

• Advanced Torque Management

Whether the car is used for drag racing, road racing, roll racing, or a high-performance street build, the ECU can be configured around the application.

128MB Onboard Datalogging

The Nexus S2 includes 128MB of onboard datalogging memory.

It can record hundreds of channels at very high sample rates.

This allows your tuner to analyze:

• Boost

• Fuel Pressure

• Oil Pressure

• AFR

• Knock

• Ignition Timing

• Injector Duty Cycle

• Vehicle Speed

• Engine RPM

• Sensor Data

• Engine Protection Events

• Traction Data

• Much More

You do not need to keep a laptop permanently connected to capture important data.

Onboard Wi-Fi + USB-C

The Nexus S2 includes:

• USB-C Communication

• Onboard Wi-Fi

• Haltech NSP Software Support

• Haltech Connect App Compatibility

Wi-Fi allows remote monitoring and tuning functionality through supported Haltech software.

USB-C also provides fast communication and allows the ECU to be powered for configuration before it is installed in the vehicle.

CAN Bus Expansion

The Nexus S2 includes two CAN networks.

This makes it easy to add compatible Haltech devices such as:

• IC-7 Digital Dash

• CAN Keypads

• CAN Wideband Controllers

• GPS Modules

• I/O Expanders

• Additional Sensors

• Other Haltech CAN Devices

This gives you room to expand the electronics package as the build grows.

Expandable Inputs & Outputs

The included auxiliary connector gives you access to additional ECU inputs and outputs.

These can be used for sensors and functions such as:

• Fuel Pressure

• Oil Pressure

• Exhaust Backpressure

• Flex Fuel

• Nitrous

• Boost Control

• Fan Control

• Shift Lights

• Warning Lights

• Additional Temperature Sensors

• Additional Pressure Sensors

• Driver Switches

• Motorsport Functions

The Nexus S2 also features flexible I/O, meaning unused outputs can often be reassigned for other functions.

Perfect for Turbo B-Series Builds

For a turbo Honda, the Nexus S2 can replace multiple separate systems with one modern ECU platform.

Your tuner can control:

• Injectors

• Ignition

• Boost

• Wastegate Control

• Flex Fuel

• Launch Control

• Anti-Lag

• Traction Control

• Fuel Pressure Protection

• Oil Pressure Protection

• Wideband AFR Protection

• Knock Control

• Datalogging

This gives you much more control over both performance and engine safety.

Important: Nexus S2 Does NOT Include an Internal PDM

The Nexus S2 is a standalone ECU, but it does not contain the integrated Power Distribution Module found in some Haltech Nexus R-Series products.

Your vehicle will continue using its existing relay and fuse system unless you add a separate power distribution solution.

If you want advanced power distribution, a separate Haltech PDM such as the PD16 can be integrated through CAN.

FREE Startup Support Included

When you purchase your Haltech Nexus S2 Plug-and-Play ECU from Kugan Tuning, we also include startup and setup support.

We can assist with:

• NSP Software Setup

• ECU Communication

• Base Calibration Selection

• Injector Setup

• MAP Sensor Configuration

• Wideband Configuration

• Trigger Verification

• Sensor Verification

• Flex Fuel Setup

• First Startup

• Idle Setup

• Basic Datalog Review

• Troubleshooting Initial Setup

Our goal is to help get the vehicle connected, configured, started, and ready for final tuning.

Custom Tuning Is Separate

The included setup support and basemap assistance are designed to help get the vehicle running and ready for tuning.

A complete custom remote tune or dyno tune is not included unless specifically purchased separately.

For best performance and engine protection, your Nexus S2 should be professionally calibrated around your exact:

• Engine

• Turbo

• Injectors

• Fuel

• Boost Level

• Sensors

• Camshafts

• Compression Ratio

• Modifications

The Modern Upgrade for OBD1 Honda Engine Management

If you're ready to move beyond the limitations of an old chipped Honda ECU, the Nexus S2 gives you a modern platform that can grow with your build.

You get:

• Plug-and-Play OBD1 Integration

• Built-In Wideband Control

• Built-In 4-Bar MAP Sensor

• Flex Fuel

• Advanced Boost Control

• Drive-By-Wire Support

• Knock Control

• Multi-Level Engine Protection

• Motorsport Features

• 128MB Datalogging

• Wi-Fi

• USB-C

• Dual CAN

• Expandable I/O

• Kugan Tuning Startup Support

Upgrade Your OBD1 Honda to the Haltech Nexus S2 Today.

Get modern standalone control without completely rewiring your Honda.