JBA 03-09 Toyota 4.0L V6 w/o A.I.R. 1-1/2in Primary Raw 409SS Cat4Ward Header

If you're looking to get more out of your 2003-2009 Toyota 4Runner with the 4.0L V6 engine (without A.I.R. system), these JBA Cat4Ward headers are a solid option. They're designed to be significantly less restrictive than the factory exhaust manifolds, which can help your engine breathe better and make more power. You'll likely notice improved throttle response and a bit more pull, especially in the RPM range where you do most of your driving.

These headers are built from 409 stainless steel tubing, which is a well-built material that holds up well to the heat and stress of daily driving, towing, or even some spirited runs. The flanges are a stout 3/8-inch thick with oversized ports to match the engine's exhaust ports, and JBA uses their proprietary Firecone collector design. This design is based on race-proven technology aimed at maximizing power and torque gains where you need them most. They also include factory-style emission connections and the necessary hardware for a proper installation that should seal up well.

When installing these, you'll want to make sure you have the correct hardware and that the mating surfaces are clean for a leak-free seal. The mandrel-bent tubing ensures consistent diameter throughout, which helps maintain smooth exhaust flow.