2003-2007 Infiniti G35 Coupe Factory Intermediate Pipe, Resonator and Main Muffler Identification

No formal service supersession was verified for 20300-AM800 or 20100-AM800. The 20100-AF400 marking is shown by the catalog as a manufacturer stamp on 20100-AM800 and is not a replacement chain. Repetition of the same downstream pair across checked 2003, 2005, 2006 and 2007 Coupe diagrams does not prove G35 Sedan, 350Z, G37/Q60 or non-US interchange. Separately cataloged front/Y-pipe production branches are an upstream fitment boundary and are outside this row.

Begin with both VINs/builds and confirm CV35 Coupe, production, installed VQ35DE equipment and transmission; do not choose from a seller's G35, Rev-Up, 5AT, 6MT or cat-back label alone. Match the retained front/Y-pipe outlet to the 20300-AM800 inlet, then compare pipe length and routing, resonator shell, flange count/orientation and gasket seat, 20100-AM800 shell and outlets, hanger/bracket positions, rubber isolators, heat shields, underbody clearance and even tail-outlet position at the bumper. Require actual-piece photographs and written inclusion of the intermediate pipe/resonator, main muffler/outlets, new required gaskets, bolts/nuts, brackets, mounts/isolators and shields. InfinitiPartsDeal displayed the intermediate assembly at 64.9 x 9.8 x 4.0 inches and 12.40 pounds and the main assembly at 43.4 x 33.6 x 14.3 inches and 55.60 pounds; treat these as catalog shipping references that demonstrate long/oversize freight risk, not installed measurements. Reject crushed or kinked pipe, perforation or severe scale, cracks, warped flanges, broken studs, loose or removed internals, impact damage, missing sections, non-factory cutting/welding, altered outlets, hidden coatings/repairs or freight damage. The service manual calls for new exhaust gaskets during reassembly, proper mounts without undue stress, an even tail-to-bumper gap, and a final leak/noise check. Work only on a fully cooled system with qualified lifting and exhaust service; retain all certified emissions equipment and verify current noise/emissions rules.

A VIN/build-correct factory 20300-AM800 and 20100-AM800 pair is the reference restoration path. AutoPartsPrime displayed Walker 54647 at $173.10 for its selected 2003 G35 page, but that aggregated listing does not prove all-year Coupe body, flange, hanger, outlet or bumper fit and is not an OEM supersession. A documented legal cat-back may be considered only after exact Coupe/VIN, retained front/Y-pipe interface, dimensions, mounts, bumper clearance, noise/emissions compliance and written contents are confirmed. G35 Sedan or 350Z assumptions, emissions deletes, universal systems and cut-and-weld conversions are outside this guide.

US/LHD 2003-2007 CV35 G35 Coupe downstream rear exhaust only. Match both VINs/builds, installed engine/transmission equipment, exact upstream flange, service identity, hangers, outlets and written contents. A manufacturer stamp is not a supersession. Do not infer Sedan, 350Z or G37/Q60 interchange. Reject cut/welded, crushed, perforated, internally loose, altered or freight-damaged parts; use new required gaskets, retain emissions equipment and verify noise/emissions legality.

Supersede reviewed 15 unique research sources for this guide. 7 also appear above as a seller or official action and are not repeated here; 8 additional citations follow.

Research last verified 2026-08-06.

1. Infiniti Parts — infiniti muffler 20100am800Open source
2. Infiniti Parts — exhaust exhaust componentsOpen source
3. Infiniti Parts Deal — exhaust tube mufflerOpen source
4. Infiniti Parts Deal — exhaust tube mufflerOpen source
5. Infiniti Parts Deal — exhaust tube mufflerOpen source
6. Infiniti Parts Deal — exhaust tube mufflerOpen source
7. Vkmotorsports — exhaust systemOpen source
8. Nicoclub — infiniti service manualsOpen source