Question on why certain parts need an EO# to be legal.

[cool 84]

This is all based on the fact that I've heard that WOT emissions are not a concern nor are they measurable.

I can understand that headers and a bigger DP can increase the time it takes for a cat to light off even though they probably have no effect on emissions once warm. Why is it that external wastegates, cold air inductions, street chips (that use factory programming when not at WOT), and probably a lot of other parts I'm forgetting are not legal? My friend's Porsche has a factory external gate that dumps after the cat and that was legal, at least in 1987.

[gofstbuick]

ARB defines those aftermarket parts that are not functionally identical to the original equipment part in all respects which in any way affect emissions must be approved via an Executive Order. Additionally, add on parts that may adversely affect the effectiveness of the vehicle emissions controls must receive ARB Executive Order approval or exemption. ARB will accept testing from outside independent sources or perform rigorous test on the product prior to issuing a EO (Executive Order). Most of the test requirements are too expensive for an individual to under take. I suspect some manufacturer (of aftemarket parts) may also feel in is not economically feasible to goe through the EO process. Take the Edelbrock Corp, they have a full blown lab for not only testing performance gains, but I'll wager that they know exactly how the product will blow on a ARB sniffer test (2 full days of federal test procedure testing). But who else has that kind of funds except major manufacturers. And the return on investment for say a SBC as compared to TR 3.8 is really no comparison.
Lots of our administrators talk about support for our vendors. Well, the EO program is a prime example of how money gets attention. This is just an opinion though. so don't go quoting it as gospel. If you require further EO information, you'll probably need to email me a phone number and I'll discuss it further with you.