My exhaust manifold was cracked, leaking pre-cat fumes into the engine bay and cabin, also the likely cause of my recent failed emissions.
So, out with the old...
And in with the new. Racing Beat 4-1 header, from Flyin’ Miata.
Mmmm... shiny. I just don’t know what to make of the fact that there’s no heat shield now. I guess Stainless steel transfers less heat than the stock pipes, I’m going to look into heat shields nevertheless.
All together it was a half-day one person job. The trickiest parts were getting the old midpipe bracket off the bell housing, and getting the oxygen sensor to reach the new location, which is substantially further downpipe than the stock location. Just popping the wire out of its support brackets gave enough slack to make it.
So I’m not sure what to expect to be different but the sound is definitely mellower without that whistling leak under the hood, and I don’t smell hydrocarbons when I stop at a light anymore. All good. It remains to be seen if I pass emissions, but I’ve spent the threshold amount for a car this age so I shouldn’t have to do anything else.