At the exhaust manifold the cat converter attaches. What is the next piece that has a small vacuum diaphragm with small hose attached? Muffler or converter? Thank you
That's the Gen 1's HCAC (hydrocarbon adsorber catalyst) bypass valve actuator. While we're on the subject, it is good to make sure it moves, and occasionally put some high-temp anti-seize lube on the ends of the valve shaft where it goes through the exhaust.
