I.L.Motorsport comes now with a brand new line of complete Stainless steel headers. This header with 4 into 2 into 1 pipes is so designed that it gives us a maximum HP and a maximum high flow. We have tested a couple of design to get to this special looking finished header.The lenght of the pipes are exact messured so that we get the best flow, the tests are done on one of the impressives Dynos we have here.
When you replace your factory exhaust manifold with an I.L. Motorsport sports header, you need to replace the second O2 sensor in the location behind the catalytic converter of the factory midpipe. That way your Miata runs correctly. The OEM manifold has a catalytic converter incorporated in it, with O2 sensor locations before and after the cat. Because a performance header removes that first cat, you’ll need to move the O2 sensors down to after the secondary cat, so that the check engine lamp will not illuminate. You need to install the stainless steel bung in a fixed position located behind the second converter in the midpipe. These extension wires are made in the optimally length to connect it plug & play in the oem wiring harness. The wiring extension can be found here. A detailed installation instruction is included.
The omission of a catalytic converter changes the exhaust gas values and the mixture composition.
We therefore recommend that you always have the control unit adjusted in order to achieve optimum performance and best possible engine running with the installed exhaust gas components.