This is what I'm unclear on. Does every aftermarket catalytic converter need CARB/EPA approval now? Including generic brand replacements for the average vehicle? If not, what are the criteria used to determine a non compliant aftermarket catalytic converter vs. a compliant one? Are only OEM replacements considered compliant? Any aftermarket catalytic converter is likely to operate at least slightly outside of an OEM cat's specifications.
I've read the sections of the clean air act that pertain to automotive modifications. There is nothing specific about any parts or criteria that parts need to meet to be considered in or out of compliance. Under the reinterpretation, it simply states, that no modifications can be made which alter the OEM emissions specifications of the vehicle. Under that vague definition, literally anything from fuel cells and cam shafts, to de-catted down pipes COULD be interpreted to change the OEM emissions specifications.
There is nothing stopping them from going back to companies like Cobb, pointing at almost any given part in their catalog, and telling them it is now considered to be out of compliance and they must apply, pay, and wait for a certification to sell those parts, with no obligation on their end for a timely review. There needs to be more specific definitions codified for this not to turn into a really tyrannical situation.
It's not that bad for now, but there is far too much room in the interpretation of the law to think they won't keep tightening the noose moving forward.
You are correct in California a catted downpipe that is not CARB approved is illegal to sell for on road use. CARB rules are actually quite specific EPA rules not so much . This is what causes the confusion.
The EPA vagueness is what drives this confusion. CARB specifically states anything that can later emissions or are part of the emissions systems. Yes a gas tank has a evap cannister attached to it so that is part of the emissions in reference to your fuel cell comment. Cam shaft alter timing and valve height , length and duratIon which can and does effect emissions output. Intakes fall into this category as well because it’s altering air flow. Current emission systems are quite sophisticated and no longer just slapped on engine like they used to do back in they day. The engines are engineered around the whole system.
Now truthfully modern ICE engines are cleaner burning because of such engineering . Though still messing with them will alter output.
Whether or not a car would still pass a tailpipe test is a whole other question.
Though current as of last ten years cars no longer get tailpipe tests. It’s all plug in the OBDII read the sensors and if they all check off they know it’s burning clean.
I am not saying I agree with all CARB’s stipulations because it’s a an agency with an agenda driven by the legislature surrounded around cleaner air. Some of the people are not exactly automotively oriented people hence sometimes draconian or ridiculous proposals get floated. Like our Governor mandate all EV new car sales no ICE by 2035 which is an almost borderline ridiculous proposal for that time frame.
COBB is going after making all their products CARB approved so they do not run in regulatory issues i.e. they want to stay in the performance business and keep it alive yet not run afoul of authorities . Since a high percentage of performance enthusiasts live in California especially SoCal it’s important to their business model. A lot of people outside of California fail to realize or forgot that this was/is ground zero for sports cars and performance cars for years. The whole Euro tuning and Japanese sports and tuning started here. It was also a big hotbed for drag racing as well. Though it has gotten harder their is still a larger performance car community in a single geographical region than most other states.
As far as sale of non legal products go any company can do as they please and risk issue if they have a instate presence . Out of state unless they are trying to tow the line like COBB they will still probably sell something not legal for street use to owners in California . For reasons like their state may not care or follow CARB guidelines.
It is actually more unclear to out of state people than us here we technically know exactly what we can and can‘t do to our cars whether we choose to follow the rules or not . The 8 year till official smog requirement that is in place for new car ( used to be 6) has been around for over 10 years in the 6 year and then 8 which started back in 2017 . That kinda opened a mod window we’re you could get away with otherwise illegal performance mods and not worry unless caught and sent to a referee . Which can be avoided one is careful.
That is what a lot do. Mod till they need a smog and then demod so they can smog.
I hope this cleared it up for you.