Approval Details

Valid E.O.


This Executive Order approved the specified parts on on September 29, 2008.
As of Sunday, July 21st, 2024 this Executive Order has not been overturned or superceeded.

Approved Parts

1996-2008 off-road compression ignition engines of 10.8 liter or less displacement.This exemption limits installation of one ME-1 Hydrogen Generator unit per engine.

This Executive Order may be listed as:
  • C.A.R.B.E.O. D-638U
  • Executive Order 638U / D638U
  • ARB # D-638U
  • Executive Order No: D-638U
  • C.A.R.B. No. D-638U
  • Resolution D-638U
For Free CARB Executive Order Status verification, email an image of the device Executive Order label as well as the Year/Make/Model and Test Group # of the vehicle to [email protected]

Download: Executive Order D-638U PDF

D-638U Document:

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