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1990 Toyota 4Runner Exhausts & Mufflers
Exhausts & Mufflers
Your vehicle’s exhaust system is an integral component of the powertrain; like the air intake system, the exhaust is tasked with transporting gasses around the engine. However, rather than funneling clean air into the intake manifold, the exhaust directs burnt fuel and byproducts of the combustion process out of the cylinder heads and into the atmosphere.
With that said, it’s not as simple as connecting some piping to the cylinder heads. Exhaust systems must be equally clean, efficient, and quiet, requiring hours of research, development, and numerous components, hence the title, "exhaust system.”
Exhaust System Parts
Exhaust systems contain numerous components, each serving an important role regarding increased flow, reduced noise levels, and reduced tailpipe emissions; these components include:
Catalytic Converters: Catalytic converters significantly reduce tailpipe emissions using a precious metal-embedded ceramic substrate that converts harmful compounds into carbon dioxide, nitrogen, and water vapor.
Exhaust Headers & Manifolds: Headers and manifolds collect gasses from each exhaust port in the cylinder head and direct them into a single outlet. Depending on the shape and size, headers and manifolds can significantly impact performance.
Exhaust Tips: While exhaust tips are primarily an aesthetic modification, dressing up the rearmost exposed section of the exhaust, these components can also affect sound depending on their shape and design (e.g., resonated tips).
Mufflers: Mufflers significantly impact the tone of your vehicle’s exhaust, removing unwanted frequencies and reducing volume. Depending on the construction and design, mufflers can drastically tune your vehicle’s exhaust to a desirable note!
Turbo Downpipes: Turbo downpipes are used on turbocharged applications, connecting the turbocharger exhaust housing to the exhaust system.
Y-Pipes & Mid-Pipes: Y-Pipes and Mid-Pipes are portions of the exhaust piping. Y-pipes converge both banks of the exhaust into a single outlet, while mid-pipes connect the outlet of the Y-pipe to the axle-back.