Can I use this on an automatic Civic?

No — this radiator is spec'd for manual transmission B16 motors. Automatic models run different thermal loads and require the AT-specific core. Check your transmission type before ordering.

Will I need a new radiator hose or thermostat housing?

OEM radiator bolts directly to factory hose locations and thermostat. Reuse your existing hoses and housing if they're in good condition; they're designed to match this core.

Do I need to flush the cooling system before install?

Yes — drain old coolant, flush the block and heater lines to remove sediment, then install this radiator. Fresh coolant prevents corrosion and ensures the new core runs at peak efficiency.