APDTY 12571601 Exhaust Manifold & Catalytic Converter Assembly Fits 3.5L Engines On 04-06 Chevorlet Colorado, 04-06 GMC Canyon, 06 Hummer H3, H3T, SUV(Replaces GM 12606655, 12604221) Header-Style (Welded Stainless Steel Tubes Instead Of Heavy Cast Iron) Complete Exhuats Manifold & Catalytic Converter Assembly O2 Oxygen Sensor Threaded Hole Exceeds OE Specifications Premium Quality Aftermarket Replacement Part