Route fresh secondary air where the emissions system needs it with the Standard Ignition Secondary Air Injection Pipe (AT161) — a direct-fit replacement for the listed applications. It fits a wide range of 1987–1993 Chevrolet and GMC full-size trucks, vans, and Suburbans, including the C2500, C3500, K2500, K3500, R/V2500, R/V3500, and P30/P3500 with the V8-7.4L, plus the 1992 Chevrolet C2500 Suburban with the V8-5.7L. See the Buyer's Guide tab for the full list of 31 applications.
The secondary air injection pipe carries fresh air from the air-injection pump into the exhaust stream, where it promotes oxidation of unburned fuel and helps the catalyst reach operating temperature — work that mainly happens during cold start.
- Job: channels secondary (fresh) air toward the exhaust as part of the air-injection emissions system.
- Direct fit: designed to install on the listed Chevrolet and GMC applications.
- Signs it may need replacing: exhaust or air leaks at the pipe, hissing, or a secondary-air-related check-engine code — if a failed pipe is the cause, this replaces it.
Diagnose the underlying fault before replacing, since these symptoms can have other causes.
Manufacturer part number: AT161.
