It is not illegal in my state. Headers and CATs are CA CARB Certified, so are the mufflers. So yours will also be illegal cause it didn't come with "true" duals. All our cars are "illegal" since none came with all the stuff we modified.
Dual exhaust
- Thread starter carman
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The only legal system is what the EPA certified for the chassis @ that time/period. Dual cats are illegal.
These cars only came certified w/a single cat on a main head-pipe & then split into duals (L/R into a main head-pipe, the CAT, & then out to whatever depending on the chassis). Dual cats were never certified on the G-chassis based on the research I did which makes them illegal despite trying to make things better from a 'greener' perspective.
These cars only came certified w/a single cat on a main head-pipe & then split into duals (L/R into a main head-pipe, the CAT, & then out to whatever depending on the chassis). Dual cats were never certified on the G-chassis based on the research I did which makes them illegal despite trying to make things better from a 'greener' perspective.
That is quite correct. The 1990 revision of the Clean Air Act forbids converting single cat exhausts to duals unless it was offered as a EPA certified factory option for all 50 states. Most states have no say over Federal emission laws. CA is the only state that can set its own emission laws, the EPA usually just copycats CA laws and pushes them on the other 49.
The mechanical issue is that cat converters need a certain amount of heat to operate and therefore need to be correctly sized with the engine to reach the required temperature. With a single cat it receives all the exhaust heat while dual cats each only receive half the heat. This means smaller cats must be used for a dual system and all sorts of expensive testing must be performed to verify that they clean the exhaust just as well as stock. Most inspection stations are not equipped to test custom setups due to cost, time, and difficulty.
Not all modifications are illegal. Only those that affect and degrade emissions are illegal. There used to be many EPA/CARB certified legal performance parts for our cars. However, cat converters are only certified and legal if used in a factory exhaust setup. A custom dual exhaust in a car that never had it as an option is still illegal even with CARB certified cats as they are only certified for stock setups.
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I like it. I'm not a fan of chrome! Hughes Performance PN: HP3880 add 2qts to oem capacity. I paid 197.97 a bunch of years ago, now 374 at the same place. It's called infatuations?
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I'm curious if anyone has kept the Stock Single Outlet exhaust & ran an Electric cutout in one or a True dual? lol. 🤔
One can be different, I suppose.
One can be different, I suppose.
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