Catalytic Converter, Compatible With Cadillac Escalade/Chevy Avalanche Silverado Suburban Tahoe/GMC Sierra Yukon, 4.3L V6, 4.8L/5.3L V8, Front, Left, Right, Replacement OE 15756278, 50366

If your check-engine light is on and your GM truck or SUV is throwing a P0420 or P0430 emissions code, a degraded catalytic converter is the most likely cause. This direct-fit replacement is engineered specifically for 1999-2006 Chevrolet and GMC trucks and SUVs, restoring factory exhaust performance without cutting, welding, or sourcing adapter hardware. Bolt it on, clear the code, and get back on the road. Compatibility This catalytic converter is a confirmed fit for the following vehicles equipped with a 4.3L V6 or 4.8L/5.3L V8 engine: Chevrolet Silverado 1500 (1999–2006), Chevrolet Tahoe (1999–2006), Chevrolet Suburban 1500 (2000–2006), Chevrolet Avalanche 1500 (2002–2006), GMC Sierra 1500 (1999–2006), GMC Yukon (1999–2006), GMC Yukon XL 1500 (2000–2006), and Cadillac Escalade (2002–2006). Replacement positions covered include Front, Left, and Right. This unit directly replaces OE part numbers 15756278 and 50366. Always verify your vehicle's VIN, engine code, and existing OE part number before ordering to guarantee an exact fit. Key Benefits • Bolt-On Direct Fit — Factory-matched mounting flanges and flange bolt patterns mean zero modifications on your Silverado, Sierra, Tahoe, or Yukon. No adapter kits, no exhaust shop visits, no cutting. • Clears Emissions Codes — Engineered to resolve P0420 and P0430 OBD-II fault codes caused by catalyst efficiency failure, helping you pass state emissions inspections in non-CARB states without expensive dealership repairs. • OBD III Federal Compliance — Manufactured under strict quality-control protocols to meet OBD III federal emission standards, ensuring your truck or SUV meets current exhaust regulations right out of the box. • High-Flow 400-Cell Honeycomb Core — The 400-cell ceramic substrate provides an expansive catalytic surface area for thorough exhaust gas conversion while maintaining healthy exhaust flow and preventing back-pressure buildup. • Corrosion-Resistant T409 Stainless Steel Shell — The outer housing is stamped from T409 stainless steel, resisting the road salt, moisture, and heat cycling that destroys factory converters on high-mileage GM trucks over time. • Long-Term OE-Level Performance — Unlike universal-fit converters requiring modification, this unit maintains factory exhaust geometry, preserving oxygen sensor placement and ensuring accurate fuel-trim readings from your powertrain control module. Technical Specifications • Product Type: Direct-Fit Catalytic Converter • Position: Front, Left, Right • OE Cross-Reference: 15756278, 50366 • Engine Fitment: 4.3L V6 / 4.8L V8 / 5.3L V8 • Shell Material: T409 Stainless Steel • Substrate: 400-Cell Ceramic Honeycomb Carrier • Emissions Compliance: OBD III Federal Standards (non-CARB states) • Fault Codes Addressed: P0420, P0430 • Compatible Model Years: 1999–2006 (varies by model; see compatibility section) • Installation Type: Direct bolt-on, no cutting or welding required Materials and Build Quality The durability of a catalytic converter is only as good as the materials used to build it. This unit features a T409 stainless steel outer shell — the same alloy grade used in OEM exhaust systems — chosen for its superior resistance to high heat, road chemicals, and corrosive salt spray common in northern and coastal US markets. The inner 400-cell ceramic honeycomb carrier is precision-formed to maximize the surface area exposed to exhaust gases, enabling complete oxidation of hydrocarbons, carbon monoxide, and nitrogen oxides. The catalytic washcoat applied to the honeycomb is formulated to activate quickly at operating temperature and sustain conversion efficiency across a wide thermal range. Flanges are machined to OE tolerances, ensuring a leak-free, rattle-free seal against the factory exhaust manifold and downstream piping. The end result is a converter that holds up to the thermal cycling, vibration loads, and chemical exposure that accelerate failure in budget alternatives. Installation Guide This is a straightforward bolt-on replacement suitable for experienced DIYers with basic hand tools and access to a vehicle lift or jackstands. Begin by safely raising your Silverado, Sierra, Tahoe, Yukon, Suburban, Avalanche, or Escalade and securing it on jackstands rated for your vehicle's weight. Allow the exhaust system to cool completely — catalytic converters retain extreme heat for up to an hour after shutdown. Spray the converter flange bolts and oxygen sensor threads liberally with penetrating oil such as PB Blaster and allow 15–20 minutes of soak time; this is especially important on high-mileage trucks where hardware may be heavily corroded. Disconnect the upstream and downstream oxygen sensors using an O2 sensor socket, carefully labeling each connector to ensure correct reinstallation. Remove the retaining bolts from the front and rear flanges, then slide the worn converter off the exhaust pipe. Compare the old unit to the new converter to confirm flange placement and pipe diameter match. Slide the new converter into position, thread in the flange bolts by hand first, then torque to OEM specification (typically 30–40 ft-lbs). Reconnect both oxygen sensors and verify no sensor wiring harnesses contact hot exhaust surfaces. Start the engine, check for exhaust leaks at both flanges, and use an OBD-II scan tool to clear stored P0420 or P0430 codes. Perform a complete drive cycle to allow the PCM to verify catalyst efficiency and confirm the check-engine light does not return. What's in the Box • 1x Direct-Fit Catalytic Converter (T409 Stainless Steel Shell, 400-Cell Ceramic Substrate) • Hardware: Mounting hardware may vary; confirm flange bolt reuse or source OE-spec replacements if corroded Why Shop at Expedite At Expedite, we source parts built to OE tolerances and vet every fitment claim before listing. This catalytic converter is stocked, clearly documented with OE cross-reference numbers 15756278 and 50366, and priced to save you hundreds compared to dealership pricing on a Silverado, Sierra, or Tahoe catalytic converter replacement. Our product listings include real compatibility data — not vague fitment charts — so you order with confidence. Fast US shipping gets this part to your garage quickly, and our support team is available to assist with fitment questions before you buy. We stand behind the products we carry and make returns straightforward when something isn't right. Don't let a degraded catalytic converter leave your GM truck sidelined at emissions testing or burning excessive fuel from a misfiring exhaust system. Order this direct-fit replacement today, eliminate the guesswork, and restore factory exhaust performance on your 1999–2006 Chevrolet or GMC at a fraction of dealer cost. Add to cart now and get your truck back on the road.