Front Catalytic Converter - 2002 Corvette C5 LS1

The 2002 Chevrolet Corvette C5 utilizes integrated manifold catalytic converters mounted directly to the aluminum LS1 cylinder heads. For the 5.7L (350hp) variant, the correct service replacements are GM 12556476 (driver/left) and 12556477 (passenger/right), which superseded earlier designs and eliminated Secondary Air Injection provisions for 2001+ models. These units interchange exclusively with 2001-2004 base model Corvettes equipped with the LS1; they are incompatible with 1997-2000 models featuring AIR tube ports and Z06/LS6 applications requiring distinct high-flow catalysts (12563784/12563785). When inspecting junkyard candidates, verify intact heat shields—notorious for cracking at weld seams from thermal cycling—and shake for internal substrate rattle indicating ceramic brick fracture common on tracked vehicles. Installation demands fresh manifold gaskets (GM 12555281) and copper anti-seize on oxygen sensors. Torque manifold nuts to 18 ft-lbs in proper sequence to prevent pulling threads from the soft aluminum heads, a catastrophic and frequent error during service.