Approval Details

Valid E.O.


This Executive Order approved the specified parts on on October 6, 2003.
As of Sunday, July 14th, 2024 this Executive Order has not been overturned or superceeded.

Approved Parts

Part NumberModelsModification
531500 and 5315031999 through 2003 model-year General Motors trucks, SUVs, and Hummer applications equipped with either a 4.8, 5.3, or 6.0L engine. Vehicles under the following test groups that are equipped with warm-up catalysts are excluded from this Executive Order: General Motors, 2001 model-year, 1GMXA05.3185, 1GMXA06.0188, General Motors, 2002 model-year, 2GMXA04.8183, 2GMXA04.8184, 2GMXA05.3185, 2GMXA05.3187, and 2GMXA06.0188.The Xhaust Header is a pair of medium length exhaust headers and connecting pipes that is manufactured out of 14 gage mild steel. The oxygen sensor is installed in the new 12 inch connecting pipe that is welded to the catalytic converter, similar to stock. Part no. 531500 is for vehicles without air tubes, and part no. 531503 is for vehicles with air tubes.

This Executive Order may be listed as:
  • C.A.R.B.E.O. D-374-3
  • Executive Order 374-3 / D374-3
  • ARB # D-374-3
  • Executive Order No: D-374-3
  • C.A.R.B. No. D-374-3
  • Resolution D-374-3
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-374-3 PDF

D-374-3 Document:

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