{"product_id":"exhaust-manifold-with-catalytic-converter-for-chevrolet-colorado-2004-2006-2-8l","title":"Exhaust Manifold with Catalytic Converter for Chevrolet Colorado (2004-2006) 2.8L","description":"\u003ch2 style=\"font-size: clamp(18px, 3vw, 21px); margin-bottom: 15px; line-height: 1.3;\"\u003eDirect-Fit Exhaust Manifold with Catalytic Converter for 2004-2006 Chevrolet Colorado (GMT355)\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat it Does:\u003c\/strong\u003e The Exhaust Manifold with Catalytic Converter replaces the failed factory assembly on the 2004-2006 Colorado to eliminate exhaust leaks, restore accurate upstream O2 sensor readings, and maintain federal EPA emissions compliance.\u003c\/p\u003e\n\n\u003ch3\u003eThe Stock Chevrolet Colorado Manifold Failure\u003c\/h3\u003e\n\u003cp\u003eThe factory exhaust manifold on the \u003cstrong\u003eGMT355\u003c\/strong\u003e platform frequently succumbs to extreme thermal cycling, causing the cast material to crack along the runner seams or warp at the cylinder head flange. On the Atlas \u003cstrong\u003eVortec 2800 (LK5)\u003c\/strong\u003e inline-four, this failure allows ambient air to be pulled upstream of the pre-cat oxygen sensor, throwing false lean codes (such as P0171), triggering check engine lights, and forcing erratic fuel trim corrections. Unchecked thermal stress also degrades the internal ceramic substrate of the integrated converter, causing substrate breakdown, internal rattling, and restrictive backpressure.\u003c\/p\u003e\n\n\u003ch3\u003eThe Engineering Solution\u003c\/h3\u003e\n\u003cp\u003eEngineered as a direct-fit replacement matching factory port shapes and flange geometry, this unit integrates tubular stainless steel runners and an EPA-compliant catalytic converter into a single assembly. The precision-machined, heavy-duty mounting flange ensures a flat, leak-free seal against the cylinder head, preventing cold-start ticking and exhaust intrusion into the cabin. The internal washcoat and high-flow ceramic honeycomb core guarantee complete hydrocarbon and NOx conversion while restoring factory exhaust scavenge efficiency and throttle response, directly interchanging with OEM numbers \u003cstrong\u003e12595160\u003c\/strong\u003e and \u003cstrong\u003e12571604\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003ch3\u003eWhat's Included\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e1 Exhaust Manifold with Integrated Catalytic Converter\u003c\/li\u003e\n  \u003cli\u003eExhaust Manifold Gaskets\u003c\/li\u003e\n  \u003cli\u003eInstallation Studs and Nuts\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003cdiv style=\"overflow-x: auto; margin-bottom: 20px;\"\u003e\n  \u003ctable width=\"100%\" style=\"border-collapse: collapse; border: 1px solid #e0e0e0; font-size: 14px; min-width: 300px;\"\u003e\n    \u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eFitment\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003e2004-2006 Chevrolet Colorado\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eEngine \/ Chassis\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003eVortec 2800 LK5 \/ GMT355\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eStock Output\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003e175 hp \/ 185 lb-ft\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eReplaces OEM Part #\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003e12595160, 12571604, 641216, 674851, 50458, 16612\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e2004 Chevrolet Colorado 2.8L L4 Base \/ LS \/ Sport \/ Z71 \/ Z85\u003c\/li\u003e\n  \u003cli\u003e2005 Chevrolet Colorado 2.8L L4 Base \/ LS \/ Sport \/ Sport LS \/ Z71 \/ Z71 LS \/ Z85 \/ Z85 LS\u003c\/li\u003e\n  \u003cli\u003e2006 Chevrolet Colorado 2.8L L4 LS \/ LT \/ WT \/ Z71 \/ Z71 LS \/ Z85\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eFrequently Asked Questions \u0026amp; Fitment Warnings\u003c\/h3\u003e\n\u003ch4\u003eDoes this fit the GMT355 Colorado?\u003c\/h4\u003e\n\u003cp\u003eYes, this is a direct fit for the 2004-2006 Chevrolet Colorado equipped with the 2.8L \u003cstrong\u003eLK5\u003c\/strong\u003e engine. \u003cstrong\u003eThis part is EPA compliant for federal emissions vehicles only; it is not legal for sale or use on California emissions vehicles and cannot be shipped to California, Colorado, New York, or Maine.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003ch4\u003eWhat is the proper installation procedure to prevent future exhaust leaks?\u003c\/h4\u003e\n\u003cp\u003eClean the cylinder head mating surface thoroughly, torque the included hardware evenly from the center fasteners outward, and re-torque all nuts after the initial heat cycle.\u003c\/p\u003e\n\n\u003ch3\u003eThe Chevrolet Truck Standard\u003c\/h3\u003e\n\u003cp\u003eMidsize work trucks require sustained exhaust sealing and proper backpressure balance under continuous payload demands. This replacement manifold restores factory structural integrity and eliminates exhaust leaks, preserving low-end torque for reliable hauling and daily fleet duty.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":67896177066232,"sku":"DS-EPNAOSK2F","price":248.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0800\/1290\/2648\/files\/exhaust-manifold-with-catalytic-converter-for-chevrolet-colorado-2004-2006-2-8l-1.jpg?v=1793293494","url":"https:\/\/performancechiptuning.com\/es\/products\/exhaust-manifold-with-catalytic-converter-for-chevrolet-colorado-2004-2006-2-8l","provider":"Performance Chip Tuning","version":"1.0","type":"link"}