1. I replaced the valve cover gasket on my car today, and I acidentally proke the pvc valve. I just plugged the holes and drove it after words without any noticable differences. Is there any? besides the slitely higher idol?
2. I unhooked the O2 sensor on the intake manifold above the catilatic converter, and the check engine light didn't come on. My dad said that it would mess with way the car ran. He said it would it pump more fuel into the engine. This might be a good way to gain a hp or 2. I'm going to try and hollow out the cat tomorrow to see if I can pick up a cuple more hp. I'm home for spring break so I've got to do as much as I can wile I have a full garage and a lot of tools.

Go spring break celica time.

W/o a cat, i doubt your engine would dump more fuel in. And if it did, you'd just run rich and not get more power. Your gas mileage would just suck.

Removing the O2 sensor will affected your car, however not positively. Leave the O2 sensor in. Gutting the cat will help you gain a few hp, have fun with that though. The PCV valve should be left open, alot of people generally put a catch can . Depending on where you broke it, this may not be possible. Plugging it shouldnt harm the engine.