A wideband oxygen sensor (also known as UEGO - Universal Exhaust Gas Oxygen sensor) is a crucial tool for tuning your Honda's engine. Unlike the stock narrow-band O2 sensor, a wideband provides precise air/fuel ratio measurements across a wide range, allowing for accurate tuning and monitoring of your engine's performance.
This guide will walk you through the process of installing and configuring a wideband sensor on your OBD1 Honda ECU. The installation is straightforward and requires only basic tools and wiring knowledge.
Although this guide is intended for AEM brand widebands, the same concepts and principles can be applied to other brands, as long as you apply the battery offsets that correspond to each model.
This wiring method is compatible with both the Hondata S300 and other hardware solutions, as we'll be connecting to the stock O2 sensor signal pin. However, if you have a Hondata S300, you may prefer to use the board's digital inputs (refer to the Hondata wiring section).
Use a T-tap splice connector to connect the wires - no cutting is necessary.
If your ECU has a Jumper Harness, connect to those wires instead to keep your factory wiring intact.
Follow the reference table below for the wideband connections:
Wiring Reference Table
Description
Wideband
ECU
Power
RED
A25 (YELLOW on BLACK)
Power Ground
BLACK
A24 (BLACK)
+ Analog Output (5v)
WHITE
D14 (WHITE)
- Analog Output (Not all models have this output wire)
BROWN
D22 (GREEN on WHITE)
Connecting the Brown wire will provide the best ground with the least interference, thus needing little to no Voltage Offset correction.
Launch Honda Tuning Suite after installation to begin configuration.
Configure Wideband Settings
Navigate to File > Settings > Wideband to open the Configuration Dialog.
Select ECU Pin
Select pin D14 for the wideband's signal input.
Pin D14's voltage limit of 3.8V corresponds to an AFR reading of 16.0 or higher. This is due to the nature of the circuit.
ECU PIN selection for wideband input
Configure the Voltage to Lambda/AFR conversion table
Do this by either selecting one of the presets or by specifying custom offsets.
HTS has predefined values for both "old" and "new" models. The "new" model refers to the X-series, which is already corrected in version 2.22F2.
If your wideband isn't listed here, use the "Custom" list item and input your wideband's voltage to lambda scaling values, which are always referenced in the manual.
Pre-configured values in HTS 2.22F2Pre-configured values in HTS 2.15
Custom Offsets
Skip this paragraph if you're not using custom offsets (if you haven't selected the "Custom" list item in the "Wideband" dropdown).
When configuring custom values, ensure your wideband's output range is suitable for your needs. If your wideband doesn't have an acceptable range (for example, if 3.75v doesn't reach 15 AFR), you must configure its output to something suitable. Alternatively, you can use the less desirable option of using D12 (EGR) and removing resistors from the ECU's board, but this method works only on non-JDM ECUs.
AEM X-series scaling table
Calibrate Offset Correction
If you have a gauge display, adjust the offset value (using -/+0.00) until the AFR reading in HTS matches what your gauge shows.
Offset Correction Factor adjustment in HTS 2.15
Configuration using Hondata SManager (S300 board)
The configuration process in SManager follows similar steps to those described for HTS above.
Wiring
Connect your wideband's analog output to any of the S300's analog input pins (labeled A0 through A7). For widebands with an analog ground wire, connect it to the S300's analog ground pin (labeled GND) for optimal signal quality.
For best results: Use thick gauge wire for grounding, keep ground wires short, and connect both the wideband and ECU grounds to the same point. This minimizes voltage differences between components.
AEM 30-4100 with single analog output connectionAEM 30-2310 with analog output and ground connection
Check the captcha to verify you're not a robot, then click the big red button.
Launch Software
Launch SManager after installation to begin configuration.
Configure Wideband Settings
Navigate to Options > Settings > Closed Loop / Closed Loop Advanced for whichever settings you need first.
Closed Loop
General overview of Closed loop parametersClosed loop operation settings interfaceClosed loop operation mode selection dropdown
Closed Loop "Advanced"
Overview of advanced Closed loop settingsAdvanced Closed loop Input Source selection and Voltage offset input.Wideband input source selection for advanced Closed loop
Help File
Hondata provides comprehensive documentation in their help files, accessible both within the software and on their website. Each tab contains detailed explanations and tips to help you configure the settings correctly.
