Do I need to replace my exhaust manifold gaskets before installing this header?

Yes. Use fresh OEM or quality aftermarket gaskets on both the cylinder head and collector flange. Old gaskets can leak under header pressure.

Will this fit my existing exhaust system and O2 sensors?

The collector outlet matches factory dimensions. Confirm your downstream piping and O2 sensor locations before install — some secondary sensors may need relocation depending on your setup.

What's the break-in procedure after installation?

Run at moderate RPM for the first 50 miles to stabilize gasket seals and allow stainless tubes to thermally cycle. Avoid hard acceleration until the header is fully seated.