Will the O2 sensor port fit my existing sensor?strong>

The port is a standard M18x1.5 thread — compatible with most OEM and aftermarket sensors. If you're running a sensor with a non-standard thread, an adapter will be needed.

Do I need to remove the manifold to install this?

No. You unbolt the old flex pipe at the 3-bolt flange, slide the new one in, and re-torque. The manifold stays bolted to the head — job takes under an hour with basic hand tools.

Is this a direct bolt-in, or do I need to modify anything?

Direct bolt-in at the manifold flange. Make sure your downstream piping is 2.50" or larger to mate cleanly with the outlet. If you're running 2.25" piping, you'll need a reducer.