The downpipe is the first exhaust section bolted to your turbocharger — and it's one of the highest-impact performance upgrades you can make on any turbocharged vehicle. A restrictive factory downpipe chokes exhaust flow, builds backpressure, and slows turbo spool. Replacing it with a larger, free-flowing aftermarket unit drops backpressure, spools the turbo faster, and unlocks power that's otherwise trapped by the OEM system.

Catted vs. Catless Downpipes

Catless downpipes remove the catalytic converter entirely for maximum flow and maximum power gains — typically 20–40whp on most platforms. They will trigger a check engine light (P0420/P0430) and will not pass emissions testing. For track-only or off-road vehicles only.

High-flow catted downpipes replace the restrictive factory cat with a 200-cell or 300-cell high-flow metallic catalyst. You get 80–90% of the power gains of going catless while keeping emissions compliance and avoiding check engine codes on most applications. This is the right choice for street-driven cars.

Sizing Matters

Factory downpipes on most turbocharged 4-cylinder platforms are 2.0–2.5 inches in diameter. Most aftermarket upgrades step up to 3.0 inches. On bigger engines (2.0T, B58, EJ25), 3.5-inch units are available. Match your downpipe diameter to your turbo outlet — going too large on a small turbo can hurt low-end response.

Top Brands We Carry

Invidia — excellent fitment, N1 cat-back pairing, popular on Subaru/Honda/Hyundai platforms. Milltek — UK-engineered, premium stainless, strong on VAG and BMW applications. Mishimoto — lifetime warranty, direct-fit on popular platforms. AMS Performance — used on record-holding builds, top choice for Evo and GT-R. ETS (Extreme Turbo Systems) — high-flow units built for serious power levels.

Will It Throw a CEL?

Catless downpipes will trigger P0420 on most vehicles. Catted high-flow units typically do not, but some OBDII systems are sensitive — an O2 spacer or ECU tune resolves this in most cases. We stock both options across all major platforms.

Free shipping on all orders. Need help confirming fitment for your specific vehicle? Contact us — we'll make sure you get the right unit before you order.