CARB Executive Order · Throttle Body
EO D-550-47
Advanced Flow Engineering · Silver Bullet Throttle Body Spacer
- Executed
- August 2021
- Rows shown
- 9
- PDF pages
- 3
Vehicles and part numbers in Exhibit A
Excluding: FHNXV02.44K3, GHNXV02.44K3, GHNXV02.44K3, DHNXV02.4NC3, EHNXV02.46C3, GHNXV02.45K3, HHNXV02.42K3, FHNXV02.43K3, AHNXV02.4KC3, 8HNXV02.4EMC, 6HNXV02.4TC3, BHNXV02.4RC3, CHNXV02.4MC3
Excluding: HHNXV03.5GK3, GHNXV03.5KK3, FHNXV03.5MK3, EHNXV03.5SC3, 8HNXV03.5BMC, 9HNXV03.5EC3, DHNXV03.5VC3
Excluding: FHNXV03.5VK2, GHNXV03.5PK3, EHNXV03.52G2, JHNXV03.5BK3, KHNXV03.5FL3, HHNXV03.5LK3
Compare other brands for these vehicles
What the EO says about the part
The Silver Bullet Throttle Body Spacer consists of the following main components: an aluminum spacer plate, approximately one-inch thick with machined helical grooves on the inside ports, and is installed adjacent to the vehicle's throttle body or carburetor. No changes are made to any other components of the stock engine, including engine calibration.
Quoted from EO D-550-47. The EO exempts the part from California Vehicle Code Section 27156 only for the vehicles it lists.
More EOs from Advanced Flow Engineering
All 61 Advanced Flow Engineering EOs we read All vehicles with an EO-listed throttle bodySource: CARB Executive Order D-550-47 (PDF), retrieved November 11, 2026. EOs can be amended, superseded or revoked; CARB's copy is the authority. Independent reference, not affiliated with CARB.