{"product_id":"aa-signature-downpipe-b58","title":"Active Autowerke Signature Downpipe — B58","description":"\u003cp\u003e\u003cstrong\u003eActive Autowerke catted downpipe for the B58 — a big-bore, street-legal-equipment Stage 2 gateway.\u003c\/strong\u003e Opens the gating restriction while keeping a high-flow cat in the pipe.\u003c\/p\u003e\n\u003ch3\u003eConstruction\u003c\/h3\u003e\n\u003cp\u003eGenerously sized: 4.5\" stainless tapering to 3.5\" through a stainless flex joint, then to 80mm to meet the OEM system — never below the factory 80mm. 4.5\" GESI G-Sport Ultra High Output cat (EPA-registered, 49-state \/ OBD2, no CEL; not CARB). Ships with the turbo flange gasket.\u003c\/p\u003e\n\u003ch3\u003eWhere it fits in the build\u003c\/h3\u003e\n\u003cp\u003eDownpipe-side core of a B58 Stage 2 build; we calibrate around it. The \u003ca href=\"\/products\/stage-2-kit-b58\"\u003eStage 2 Kit — B58\u003c\/a\u003e bundles parts + tune for 8% under à la carte.\u003c\/p\u003e\n\u003ch3\u003eFitment\u003c\/h3\u003e\n\u003cp\u003eBMW B58 (single-turbo, 2024 \u0026amp; earlier) — M240i (F22\/G42), 340i \/ M340i (F30\/G20), 440i \/ M440i (F32\/G22), Z4 M40i (G29). Confirm your chassis in the selector.\u003c\/p\u003e","brand":"Active Autowerke","offers":[{"title":"Catted (GESI)","offer_id":43280704208957,"sku":"11-AA-B58","price":1805.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0658\/2553\/8109\/files\/aa-g20-b58-catted-downpipe_01.webp?v=1781743119","url":"https:\/\/essewerks.com\/products\/aa-signature-downpipe-b58","provider":"Esse Werks","version":"1.0","type":"link"}