QuestionQUESTION: I have a Cosmo with all the stock parts. It will not pass smog check in California. Is there something I can do to retify this. Is replacing the thrmal reactor with a cat the solution, even though I may have a problem with the visual inspection?
ANSWER: Basic preventive maintenance first.
Oil & Filter - 5w30 full synthetic is recommended
A new set of NGK plugs and wires both Lead and Trail. Denso or NGK Iridium for the Lead plugs are best.
Air Filter
Clean the carburetor
Clean the ACV and the line that feeds the thermal reactor. Proper air flow is required for the reactor to work correctly. Inspect it for any outward signs of cracking.
These are the most common steps to making them efficient and if your only marginally failing it could be the difference. If it is a gross failure then other issues need to be addressed.
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QUESTION: Everything has been done. The car tested as a gross polluter. What can be done to rectify this?
AnswerI wish I could tell you more but, my familiarity with that model is quite limited and California emissions laws are not something I am up on. In later model Mazda's the addition of inline free flow converters allowed older carburetor cars to pass emissions tests here. Replacement of the TR may be required, they are prone to developing cracks within from overheating. If the car is running well, the PM issues above are all addressed and the car is not passing smoke when up to temperature then it is a breakdown in the exhaust control or the carburetor is not metering fuel properly putting un-burnt particulates of fuel in the exhaust stream.
