1. Introduction
This manual provides comprehensive instructions for the installation, operation, and maintenance of your AEM 30-4110 UEGO Air/Fuel Ratio Gauge. The AEM UEGO gauge is designed to provide accurate air/fuel ratio data, which is crucial for optimizing engine performance and preventing damage. It features a digital LED display and a sweeping LED 'needle' that visually indicates AFR changes.
The gauge utilizes a Bosch 4.9 LSU wideband sensor, known for its fast response and accuracy, and does not require free-air calibration. This product is intended for automotive use to monitor engine air/fuel ratios.
2. What's in the Box
Upon opening the package, verify that all components are present:
- AEM 30-4110 UEGO Air/Fuel Ratio Gauge (52mm / 2-1/16" housing)
- Bosch 4.9 LSU Wideband O2 Sensor
- Weld-in O2 Sensor Bung
- Wiring Harnesses (one for the UEGO sensor, one with four leads for power/output)
- Interchangeable Black Bezel
- Interchangeable Silver Bezel
- Interchangeable Black Faceplate (Lambda Ratio)
- Interchangeable White Faceplate (Air/Fuel Ratio)
- Interchangeable Black Faceplate (Air/Fuel Ratio)
Figure 2.1: Contents of the AEM 30-4110 UEGO Air/Fuel Ratio Gauge kit, including the gauge, Bosch 4.9 LSU sensor, wiring, weld-in bung, and interchangeable bezels and faceplates.
3. Key Features
- Digital LED Display: Provides precise numerical readings of the air/fuel ratio.
- Sweeping LED 'Needle': Changes color to visually indicate AFR changes from rich to lean.
- Bosch 4.9 LSU Wideband Sensor: Ensures high speed and accuracy in readings.
- No Free-Air Calibration Required: Simplifies installation and maintenance.
- Interchangeable Bezels and Faceplates: Allows customization with black/silver bezels and black/white faceplates (Air/Fuel Ratio or Lambda Ratio).
- Compact 52mm (2-1/16") Housing: Designed to fit most standard gauge pods.
- 0-5V Analog Output: Compatible with data loggers and most engine management systems for external monitoring.
- AFR Range: Displays air/fuel ratios within the 10-20 range.
4. Setup and Installation
Proper installation is critical for accurate readings and reliable operation. It is recommended that installation be performed by a qualified technician.
4.1. Sensor Installation
- Select an appropriate location in the exhaust system for the O2 sensor bung. The bung should be welded into the exhaust pipe at a location that ensures the sensor is exposed to exhaust gases but is not subject to excessive heat or condensation.
- Weld the provided O2 sensor bung securely into the exhaust pipe.
- Thread the Bosch 4.9 LSU wideband O2 sensor into the welded bung. Ensure it is tightened to the manufacturer's specifications to prevent exhaust leaks.
Figure 4.1: The AEM UEGO Air/Fuel Ratio Gauge connected to the Bosch 4.9 LSU wideband sensor, ready for installation into the exhaust system.
4.2. Gauge Mounting
The 52mm (2-1/16") gauge housing is designed to fit most standard gauge pods. Choose a mounting location that allows for clear visibility of the gauge display while driving.
4.3. Wiring Connections
The gauge connects via two harnesses. The longer harness connects directly to the UEGO sensor. The shorter harness contains four leads for power and analog output:
- Power: Connect to a switched 12V power source.
- Ground: Connect to a reliable chassis ground.
- Analog Output (0-5V): This lead provides a 0-5V signal for external data loggers or engine management systems. Refer to your data logger or ECU manual for specific connection requirements. The output range is for 10-20 AFR.
Ensure all connections are secure and properly insulated to prevent short circuits or signal interference.
4.4. Customization (Bezels and Faceplates)
The gauge includes interchangeable black and silver bezels, and black and white faceplates (for both Air/Fuel Ratio and Lambda Ratio) to match your vehicle's interior. To change them, carefully remove the existing bezel and faceplate and install your preferred combination.
Figure 4.2: The AEM UEGO Gauge displaying Lambda Ratio, featuring a black faceplate and silver bezel. This configuration is one of several customizable options.
Figure 4.3: The AEM UEGO Gauge displaying Air/Fuel Ratio, featuring a white faceplate and black bezel. This demonstrates another customizable appearance option.
5. Operating Instructions
Once properly installed and powered, the AEM UEGO gauge will begin displaying air/fuel ratio data.
5.1. Reading the Display
- Digital LED: The central digital display shows the precise air/fuel ratio value.
- Sweeping LED 'Needle': The outer ring of LEDs acts as a visual indicator.
- Rich Condition: LEDs will typically illuminate in colors indicating a rich mixture (e.g., green/yellow).
- Lean Condition: LEDs will typically illuminate in colors indicating a lean mixture (e.g., orange/red).
- Stoichiometric (Ideal) Condition: The LED will typically be in the middle range, often yellow or a neutral color.
The gauge displays AFR values within the 10-20 range. Values outside this range may be indicated by a "---" display or other error indicators.
6. Maintenance
The AEM 30-4110 UEGO Air/Fuel Ratio Gauge is designed for minimal maintenance.
- Sensor Calibration: The Bosch 4.9 LSU sensor used with this gauge NEVER requires free-air calibration. Do not attempt to calibrate the sensor.
- Sensor Lifespan: Wideband O2 sensors are wear items. Their lifespan can vary depending on fuel type, engine condition, and operating environment. Regular inspection of the sensor for deposits or damage is recommended.
- Cleaning: Keep the gauge display clean using a soft, dry cloth. Avoid abrasive cleaners.
7. Troubleshooting
If you encounter issues with your AEM UEGO gauge, consider the following common troubleshooting steps:
- Gauge Displays "---": This typically indicates that the sensor is not reading a valid air/fuel ratio.
- Verify all wiring connections are secure and correct (power, ground, sensor harness).
- Ensure the engine is running and the exhaust system is at operating temperature.
- Check the sensor for physical damage or heavy carbon deposits. A faulty sensor may need replacement.
- Inaccurate Readings:
- Confirm the sensor is installed in an optimal location in the exhaust, away from exhaust leaks.
- Ensure the sensor is the correct Bosch 4.9 LSU type for this gauge. Note that 4.2 LSU sensors are not compatible.
- Check for proper grounding of the gauge and sensor.
- No Power to Gauge:
- Verify the 12V power source is active and fused correctly.
- Check ground connection for continuity.
If troubleshooting steps do not resolve the issue, contact AEM technical support for further assistance.
8. Specifications
| Model Number | 30-4110 |
| Brand | AEM |
| Gauge Diameter | 52mm (2-1/16 inches) |
| Sensor Type | Bosch 4.9 LSU Wideband O2 Sensor |
| AFR Display Range | 10-20 AFR |
| Analog Output | 0-5V (10-20 AFR range) |
| Material | Plastic |
| Product Dimensions (L x W x H) | 2.17 x 2.76 x 2.17 inches |
| Item Weight | 1.39 Pounds |
| UPC | 840879023157 |
9. Warranty and Support
For detailed warranty information, please refer to the official AEM product documentation or contact AEM directly. AEM provides technical support for their products.
An official installation manual in PDF format is available for further reference:
Download AEM 30-4110 Installation Manual (PDF)
For additional support or inquiries, visit the official AEM website or contact their customer service department.
