Advanced Flow Engineering

CARB Executive Order · Header

EO D-550-49

Advanced Flow Engineering · Twisted Steel Headers

Executed
October 2021
Rows shown
—
PDF pages
3
Open the original EO PDF
We show basic details only for this EO. Its table layout did not match the columns we can read with certainty, so we do not copy it. Check the vehicles and part numbers in the original PDF.

What the EO says about the part

The Twisted Steel Headers are designed to replace the factory exhaust manifolds. They are made out of 304 stainless steel. The factory oxygen sensors are reconnected to the Twisted Steel Headers. The Twisted Steel Headers also include M18x1.5 thread auxiliary bungs that shall only be used for installing pyrometers or additional oxygen sensors.

Quoted from EO D-550-49. The EO exempts the part from California Vehicle Code Section 27156 only for the vehicles it lists.

More EOs from Advanced Flow Engineering

PreviousD-550-48MACH Force-XP Turbo Down-Pipe and Atlas Turbo Down-Pipe NextD-550-50Momentum ST Cold Air Intake System, Magnum FORCE Stage-2 Cold Air Intake System, Magnum FORCE Stage-2 XP Cold Air Intake System, Momentum GT Cold Air Intake System, and Quantum Cold Air Intake System
All 61 Advanced Flow Engineering EOs we read All vehicles with an EO-listed header

Source: CARB Executive Order D-550-49 (PDF), retrieved November 11, 2026. EOs can be amended, superseded or revoked; CARB's copy is the authority. Independent reference, not affiliated with CARB.