Approval Details

Valid E.O.


This Executive Order approved the specified parts on on July 24, 2003.
As of Monday, May 27th, 2024 this Executive Order has not been overturned or superceeded.

Approved Parts

Part NumberModelsModification
THY-3092002-2003 General Motors trucks and motorhomes 4.8/5.3LThe Summit Industries, Inc.'s Thorley Headers are a shorty style header, manufactured out of 14 gage mild steel. The headers bolt to the stock connecting pipes and retain the oxygen sensor in the stock location.

This Executive Order may be listed as:
  • C.A.R.B.E.O. D-540-1
  • Executive Order 540-1 / D540-1
  • ARB # D-540-1
  • Executive Order No: D-540-1
  • C.A.R.B. No. D-540-1
  • Resolution D-540-1
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-540-1 PDF

D-540-1 Document:

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