SpeedFactory OBD0 MPFI to OBD1 Jumper Harness for 88-91 Honda

SpeedFactory OBD0 MPFI to OBD1 ECU Jumper Harness for 88-91 Honda/Acura

If you're running a B-series or upgraded OBD1 ECU swap in an older 88-91 Honda Civic, CRX, or 90-91 Acura Integra, this is the harness that makes the conversion clean and straightforward. The SpeedFactory OBD0 MPFI to OBD1 ECU Jumper Harness lets you plug a JDM or USDM OBD1 manual transmission ECU directly into your OBD0 chassis harness - no cutting, no splicing, no hacked-together wiring on a car you've put real work into.

Why do the OBD0 to OBD1 conversion in the first place? OBD1 ECUs (like the P28, P30, P72, and P61) are the go-to base for chipped or socketed tuning. They support VTEC, knock sensor input, and a 4-wire oxygen sensor, all of which your factory OBD0 ECU either doesn't support or handles differently. If you're doing a VTEC swap, chasing a proper fuel tune, or just want access to the wider range of OBD1 ECU options, this jumper harness is the first part on the list.

SpeedFactory built this harness with OEM-style ECU pin connections so you're not fighting fitment. The 7-inch extended leads give you enough slack for clean routing inside the cabin, and the included 3-foot pigtail covers the additional sensor wiring you'll need - specifically the 4-wire O2 sensor, VTEC solenoid and pressure switch, knock sensor, and IAB solenoid (where applicable). Wire gauge and insulation quality exceed factory spec, so it's built to hold up long-term under real-world heat and vibration.

Key Features:

• Plug-and-play OBD0 to OBD1 ECU conversion for 88-91 Honda/Acura MPFI chassis
• Supports JDM and USDM OBD1 manual transmission ECUs (P28, P30, P72, P61, and more)
• Compatible with 1988-1991 Honda Civic/CRX HF, Si, EX (MPFI) and 1990-1991 Acura Integra
• OEM-style ECU pin connections - no cutting or soldering required for standard applications
• 7-inch extended harness leads for flexible, clean cabin routing
• Includes 3-foot pigtail for 4-wire O2 sensor, VTEC solenoid/pressure switch, knock sensor, and IAB solenoid wiring
• Automotive-grade wire exceeding OEM specifications for long-term durability
• Note: STD and DX Civic/CRX models require additional wiring - MPFI only

What Else You'll Need to Complete the Conversion:

This harness handles the ECU-side of the swap. To complete a full OBD0 to OBD1 conversion, you'll also need an OBD1 distributor, a 4-wire OBD1 oxygen sensor, and the OBD1 ECU itself. If you're adding VTEC, make sure your engine has the corresponding solenoid and pressure switch already installed before wiring through the pigtail.

Installation:

Plug the OBD1 side of the harness into your ECU and the OBD0 side into your existing chassis harness. Route the 3-foot pigtail to the appropriate engine bay sensors. The connection points are labeled and follow OEM pin assignments, so if you're comfortable with a basic Honda swap, this install is straightforward. Always verify ECU compatibility with your specific engine and intended tune before purchasing.