This is a Hondata modified 2002-2004 RSX ECU and an adapter harness for the 05-06 RSX

Hondata makes hardware modifications to the 2002-2004 ECU enable it to work with the different sensors and actuators found on the 2005-2006 ECU. After these modifications the ECU will not function correctly on a 2002-2004 RSX.

Hondata only sells adapter harness with the modified ECU. An unmodified 02-04 ECU with adapter harness (with or without KPro) will not work on a 05-06 RSX without the internal ECU modifications performed by Hondata.


Within USA this product is legal only for racing vehicles which may never be used upon a highway.


   Price    Description
   $250    Upgrade an already K-Pro'd ecu for use in an 05-06 RSX (includes adapter harness and ECU modification)
   $845    K-Pro for 2005-2006 RSX includes adapter harness (user supplied 02-04 ECU)
   $1740    K-Pro for 2005-2006 RSX includes adapter harness (with new 02-04 PRB ECU)


The 05-06 K-Pro is only certified to work in an 05/06 RSX. Engine swaps using an 05-06 RSX engine and gearbox into another chassis are not supported with the 05/06 K-Pro and adapter harness. The correct method is here: Hyperlink to:

Application Notes

  • An primary oxygen sensor from the 02-04 RSX or 02-05 Civic Si must be used.  The 05-06 RSX O2 sensor will not work.
  • Some sensors must be disabled to eliminate errors generated by the ECU.
  • The speed sensor spins about 100 times faster on the 05/06 RSX gearbox as compared to the 02-04 RSX. Above 65-70 MPH cruise control may not function smoothly and may cancel from time to time. Also see Tech - K20 Transmissions

Which Donor  ECU can I use?

Only the following ECUs can be used.

  • 2002-2004 RSX Type S (PRB A03-A08, PRB-305 ECU).  Should be used for a Type S
  • 2002-2004 RSX (Base 5 speed) (PND -A0# ECU) Should be used for a Base

The stock 2005-2006 ECU part number PRB-A13 through PRB-A16 has a different microprocessor and cannot have a K-Pro installed.

Adapter Harnesses

These are the only harnesses that are guaranteed to work with the 05/06 K-Pro. These adapter harnesses are sold only with an 05-06 RSX-K-Pro.



 - Blue Wire
 - Sticker stating 05/06 Adapter (some adapters may not have stickers)
 - Three white plugs or
 - Two white plugs and a grey plug (from about June 2007)

If you are are having problems you may have a counterfeit adapter harness.  To verify if you have a genuine adapter harness, contact Hondata with the serial number of your K-Pro.

KPro 05-06 RSX

Upgrade from ECU with existing K-Pro ($250)
  • Restriction
    EPA/CARB status (USA) Competition vehicles only
    Model RSX
    Year 2005-2006
    Transmission MT
    Part Number PRB (A01-A12 & 305)
    PND (A01-A09)

25911 104th Ave SE Kent, WA 98030

Contact: 253.872.0872

Fax: 253.872.0778

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