ok cool... now i looked at where it is... and why did they put it against the block? Is it possible to remove the O2 sensor without taking the exhaust manifold off?

Also do you know how much they are brand new or second hand?

Knowing a honda part i expect them to be expensive. Put it this way, i went to price a new windscreen water pump. I expected to pay something like $30au or $20us... anyway the dude told me it was $93au or $61us. anyway, i replaced it with a cheap toyota part. Costed me $15au.

I'm already planning to get the suspension in my car modified. But i was looking at modifying the cams. How much HP increase would you expect from ZC cams?