Converting an OBD0 Honda engine to OBD2 can seem daunting, but with the right knowledge and parts, it’s a manageable process. This guide will walk you through the key differences between these On-Board Diagnostics systems and outline the steps required for a successful conversion.
Understanding OBD Systems in Honda Vehicles
Honda, like other manufacturers, has evolved its engine management systems over the years, leading to different OBD generations. Each system has its own diagnostic capabilities and complexities.
OBD0 (Pre-OBD)
Found in most 1988-1991 Civics and Integras, OBD0 is often considered less reliable due to its reliance on vacuum lines and a more complex diagnostic procedure. Troubleshooting often involves checking flashing lights on the ECU, making it less user-friendly for the average enthusiast. Distributor issues are also a common problem in OBD0 systems.
OBD1
This system, prevalent in 1992-1995 Hondas (including 1990-1993 Accords), offers greater reliability and simpler diagnostics. OBD1 is widely favored for its ease of reprogramming, making it popular for tuning enthusiasts. Checking engine codes is significantly easier than OBD0.
OBD2
Introduced in 1996, OBD2 brought standardized diagnostics across car manufacturers. Honda implemented two sub-versions: OBD2a (1996-1998) and OBD2b (1999-2001+). While OBD2 offers good tuning options, many enthusiasts prefer using a jumper harness with a reprogrammed OBD1 ECU for greater control over engine parameters. Some Hondas transitioned to CAN-based computers after 2001, while others continued using OBD2b.
Converting from OBD0 to OBD2
Converting an OBD0 engine to OBD2 involves swapping key components to ensure compatibility with the newer system. The primary parts that need to be exchanged include:
- Distributor: Use a distributor compatible with the target OBD system (OBD1 or OBD2). For example, converting a B20B (OBD2) to OBD1 requires an OBD1 Integra LS distributor or a modified OBD0 distributor with swapped internal components.
- Fuel Injectors: Replace the OBD0 injectors with OBD1 or OBD2 injectors. While injector sizes may vary between engines, Honda maintains consistent fuel pressure, simplifying this step.
- Alternator: Use an alternator corresponding to the desired OBD system. In a B20B to OBD1 conversion, an OBD1 D-series alternator would be appropriate.
By replacing these three components, you effectively adapt the engine to function with the newer OBD system. This conversion allows for utilizing the benefits of OBD1 or OBD2 diagnostics and tuning capabilities while retaining the desired engine.
Conclusion
Converting a Honda engine from OBD0 to OBD2 involves swapping the distributor, fuel injectors, and alternator. While this process requires careful component selection and installation, it provides access to more modern engine management systems. Understanding the nuances of each OBD generation is crucial for a successful conversion. By following these guidelines, you can effectively upgrade your Honda’s engine management system and enjoy improved diagnostics and tuning options.
