The TurboWorks exhaust manifold is made of 100% stainless steel. Guaranteed power increase up to 10% When performing engine tuning, the exhaust manifold should be replaced at the very beginning, because the exhaust gases from the cylinder go to the exhaust manifold, which is part of the engine body, then directed to the first section of the exhaust pipe, and then to the muffler or several in series silencers and then to the exhaust tailpipe. We offer 24 months warranty for the product. We also offer lambda probe adapters that eliminate the catalyst error.