I bought a new manifold for my 2002 Honda Civic 4 door LX do I need the o2 censor for it?

The new manifold is a street header without the cat, but my old manifold had the top and bottom o2 censor. Well I be fine just leaving them out?

Hi so mister bad one what happens when you get pulled for producing so much smog.

The engine will not be able to run correctly without the O2 sensors.
The O2 sensors are to to there job metering the air/fuel ratio. The balance will not be regulated without them and you will throw codes like a beast.

There are ways to trick the ECU into thinking there are O2 sensors, ie an O2 simulator, but you have them for a reason.