The best match for a Honda or Acura ECU conversion is a vehicle-specific OBD2A-to-OBD1 or OBD2B-to-OBD1 harness. The SpeedFactory Racing OBD2A harness is for specified 1996–1998 vehicles, while its OBD2B version covers specified 1999–2001 models. The other listed products are racing safety or replacement car harnesses, not ECU conversion harnesses, so they should not be treated as substitutes.
| Product | Best suited for | What it connects or provides |
|---|---|---|
| SpeedFactory OBD2A to OBD1 | Specified 1996–1998 vehicles | OBD1 manual-transmission ECU to OBD2A engine harness |
| SpeedFactory OBD2B to OBD1 | Specified 1999–2001 vehicles | OBD1 manual-transmission ECU to OBD2B engine harness |
| 1034101 Harness System | Racing safety harness buyers | Five-point restraint system |
| RE4302 Replacement Car Harness | Buyers seeking a replacement car harness | Product details identify it as a replacement car harness |
| RaceQuip 711001 | Racing safety harness buyers | SFI 16.1-rated restraint harness |
SpeedFactory OBD2A To OBD1 Conversion Harness
Best for: A buyer with a compatible 1996–1998 OBD2A Honda or Acura vehicle who wants to use an OBD1 manual-transmission ECU. The listed applications include Civic, Integra, Prelude, CR-V, and Accord.
The harness connects the factory engine harness to an OBD1 ECU. According to the product details, installation requires no cutting or soldering: one side plugs into the ECU and the other into the factory engine harness. It is selected because it directly addresses the OBD2A-to-OBD1 conversion use case.
Limitation: The listed ECU application is for a manual-transmission ECU, and the harness is specified for OBD2A vehicles. Confirm the vehicle’s connector generation and configuration before ordering.
SpeedFactory OBD2B To OBD1 Conversion Harness
Best for: A buyer with a listed OBD2B vehicle from the later model-year range who needs to connect an OBD1 manual-transmission ECU. The listed applications are 1999–2000 Civic, 1999–2000 CR-V, 2000–2001 Integra, and 2000–2001 Accord.
Like the OBD2A version, this harness is described as a plug-in connection between the OBD1 ECU and factory engine harness, with no cutting or soldering required. Choose this version if the vehicle uses OBD2B; the connector generation is the key distinction from the OBD2A product.
Limitation: It is not listed for OBD2A vehicles, and its stated ECU application is manual-transmission. Verify both details against the vehicle and ECU before purchase.
Racing Equipment 1034101 Five-Point Harness
Best for: Someone searching for a vehicle restraint harness rather than an ECU conversion harness. The listed features describe a black nylon five-point harness system with an SFI 16.1 approval claim.
This product is included because “racing harness” can refer to a safety restraint, but it does not serve the OBD2-to-OBD1 wiring purpose. Consider it only for a restraint-system purchase, and check that its specifications suit the intended vehicle and use.
Limitation: The provided details do not specify fitment, adjustment dimensions, or installation requirements.
Racing Electronics RE4302 Replacement Car Harness
Best for: A buyer specifically seeking the RE4302 replacement car harness. The available product information identifies it as a Racing Electronics replacement car harness, but does not provide further technical details.
This is not described as an OBD2A-to-OBD1 or OBD2B-to-OBD1 ECU adapter. It is included as a related harness listing, not as a solution for a Honda ECU conversion. Check the part number and intended application with the equipment or vehicle documentation.
Limitation: The supplied features do not describe connector type, wiring function, or vehicle compatibility.
RaceQuip 711001 SFI 16.1 Racing Harness
Best for: A buyer comparing racing restraint harnesses. The listed specifications say it is black, SFI 16.1 rated, and has a 3-inch lap, 3-inch shoulder, and 2-inch sub strap.
Its dimensions make it a more specifically described restraint option than the other non-ECU listings here. It is not an engine wiring adapter, so choose it only when shopping for a safety harness and after verifying that its configuration fits the intended application.
Limitation: The supplied details do not state vehicle fitment or installation requirements.
Buying Guide: How To Choose A Conversion Harness
Does the vehicle use OBD2A or OBD2B?
Identify the vehicle’s connector generation before selecting a harness. The SpeedFactory OBD2A model is listed for specified 1996–1998 vehicles, while the OBD2B model is listed for specified 1999–2001 vehicles. Model year alone may not resolve every vehicle configuration, so confirm the connectors and application details before buying.
Which ECU and transmission type are involved?
Both conversion harness listings specify an OBD1 manual-transmission ECU. Check the ECU type and transmission configuration rather than assuming that any OBD1 ECU will work. The product details do not establish compatibility with every engine, ECU, or modified wiring setup.
Is the listing an ECU harness or a safety harness?
An ECU conversion harness connects vehicle wiring to an ECU. A racing safety harness restrains an occupant, and a replacement car harness may serve another electrical purpose. The Racing Equipment and RaceQuip listings describe restraint products; the RE4302 details do not give enough information to establish its wiring function. Do not select these products as ECU adapters based on the word “harness” alone.
What should be confirmed before ordering?
- Vehicle year, model, and OBD connector generation.
- ECU generation and manual- or automatic-transmission configuration.
- Whether the listing explicitly covers the intended conversion.
- Connector condition and any non-factory wiring changes that could affect installation.
Frequently Asked Questions
What does an OBD2-to-OBD1 conversion harness do?
It connects a compatible OBD2 vehicle engine harness to an OBD1 ECU. The correct harness depends on the vehicle’s OBD2 connector generation and the ECU configuration.
Which SpeedFactory harness is for OBD2A?
The OBD2A-to-OBD1 harness is listed for specified 1996–1998 Honda and Acura vehicles and an OBD1 manual-transmission ECU.
Which SpeedFactory harness is for OBD2B?
The OBD2B-to-OBD1 harness is listed for specified 1999–2001 Honda and Acura vehicles and an OBD1 manual-transmission ECU.
Are racing seat harnesses ECU conversion harnesses?
No. The 1034101 and RaceQuip 711001 listings describe occupant restraint harnesses, not ECU wiring adapters.
Can these product details confirm fitment for every modified vehicle?
No. The supplied information gives selected applications but does not confirm every engine swap, ECU variant, or wiring modification. Verify the exact configuration before purchase.