The exhaust manifold by TurboWorks is made of 100% stainless steel. Guaranteed power increase of up to 10%. When tuning the engine, the exhaust manifold should be replaced at the very beginning, because the exhaust gases, pressed from the cylinder, go to the exhaust manifold, which is part of the engine body, then they are directed to the first section of the exhaust pipe, then to the muffler, or several silencers arranged in series and then to the exhaust part of the exhaust pipe. In the e30 model, the assembly requires modification of the engine mount mounting. The product comes with a 24-month warranty. We also offer lambda probe adapters that eliminate the catalyst error. Additional accessories are also available for exhaust manifolds: & nbsp