I know of a way to do this for $2.99 and it doesnt mess with the car in any way and is completly reversable.
go to autozone or anyother place and purchase spark plug anti foulers (usually HELP! brand) for around $3. Take one of the two non foulers and drill it out to 1/2 inch all the way through(this allows the O2 probe to sit flush). Take both of your anti foulers and make a stack like the one shown below. The drilled anti fouler screws on to the O2 sensor and the non drilled one onto your O2 bung on the pipe. Connect the two and your good to go.
I ahve driven over 2000 miles so far on my MSP with no cats - never a CEL and still great gas milage (in fact my milage went up!)
