I recently bought a 2000 Focus which came with one PATS key. Finding that extra keys (I needed two more) were going to cost roughly $75+ each, I set off to find another solution. I found many posts that suggested pulling the transponder out of the key, but noone seemed to have actually done it. Well, I did it and...it works! You will lose a little security but I always lock my car anyway. Below are pics with directions under each picture.

The transponder is a tiny glass vial inside of which is a coil of wire and other mysterious stuff. A transmitting unit sends a signal to the transponder (no batteries) which somehow uses the signal to generate enough current to respond and allow the car to start. All this is fitted to a holder and this combo is stuffed into the key. Look at your key under a lamp and you can see the trapdoor. Use a razor blade, utility knife blade, or Exacto knife to cut along the trapdoor's rectangle and then pry out the transponder & holder.

Here's a better view of the setup.

And there it is. It's a tight fit and pulls out with a little effort. It also goes back in, but it's pretty hard. To get it back in (like if you lose you nerve...) you might heat the plastic key in the oven to something like 150 degrees and see if it slides in a little easier. But don't lose your nerve 'cause this workaround really works.

You'll find that the holder is a little too long to fit in the spot I'll recommend below. I cut the bottom 1/8" off but if I were to do it again I'd cut the top off which I could then use as a plug to cover the hole in the key's plastic. In either case put a drop of glue on the end to keep the two sides of the holder from spreading apart.

Now take off the bottom half of the steering column surround. It has three torx screws (size T-15), so go to the hardware store before you start this project and pick up the right sized driver if you don't have one. I had to jerk this surround a bit to get it removed but it came off in a few seconds. Now you can see the lock cylinder and the transponder's sending unit surrounding the cylinder right behind the key slot. It's that black plastic ring that's kind of dusty. What I was very pleased to find was that area behind the sender because it forms a little cubby that the shortened transponder/holder fits in nice and snug. Very cool.

Look closely and you'll see the holder on it's way to laying down in this perfect spot.

With all the black it may be hard to see, so I'll point it out.

There, all settled in. Time to start the car with the old key. Dang, it won't start! The dash lights go on and the security blinker by the 4-way flasher button goes nuts. But the engine isn't turning over! What's the deal?

Having fussed with the transponder earlier I knew the system was hypersensitive to its location, so I rotated the holder 90 degrees to configure it sort of vertically. Success, the car fired right up with no security LED flashing. Whew, that had my pulse racing a bit.

A strip of electrical tape slipped over the top finishes the job. After a few days of operation I may pull the tape back and pour a little glue alongside the holder, just in case the tape loses it's grip and the holder jiggles out when bouncing over a pot hole.
The project will take about an hour and is really pretty easy. Be sure to pick up the Torx driver (T-15) before you start. Good luck!
-MK
Other keywords: chip disable fob Securecode

The transponder is a tiny glass vial inside of which is a coil of wire and other mysterious stuff. A transmitting unit sends a signal to the transponder (no batteries) which somehow uses the signal to generate enough current to respond and allow the car to start. All this is fitted to a holder and this combo is stuffed into the key. Look at your key under a lamp and you can see the trapdoor. Use a razor blade, utility knife blade, or Exacto knife to cut along the trapdoor's rectangle and then pry out the transponder & holder.

Here's a better view of the setup.

And there it is. It's a tight fit and pulls out with a little effort. It also goes back in, but it's pretty hard. To get it back in (like if you lose you nerve...) you might heat the plastic key in the oven to something like 150 degrees and see if it slides in a little easier. But don't lose your nerve 'cause this workaround really works.

You'll find that the holder is a little too long to fit in the spot I'll recommend below. I cut the bottom 1/8" off but if I were to do it again I'd cut the top off which I could then use as a plug to cover the hole in the key's plastic. In either case put a drop of glue on the end to keep the two sides of the holder from spreading apart.

Now take off the bottom half of the steering column surround. It has three torx screws (size T-15), so go to the hardware store before you start this project and pick up the right sized driver if you don't have one. I had to jerk this surround a bit to get it removed but it came off in a few seconds. Now you can see the lock cylinder and the transponder's sending unit surrounding the cylinder right behind the key slot. It's that black plastic ring that's kind of dusty. What I was very pleased to find was that area behind the sender because it forms a little cubby that the shortened transponder/holder fits in nice and snug. Very cool.

Look closely and you'll see the holder on it's way to laying down in this perfect spot.

With all the black it may be hard to see, so I'll point it out.

There, all settled in. Time to start the car with the old key. Dang, it won't start! The dash lights go on and the security blinker by the 4-way flasher button goes nuts. But the engine isn't turning over! What's the deal?

Having fussed with the transponder earlier I knew the system was hypersensitive to its location, so I rotated the holder 90 degrees to configure it sort of vertically. Success, the car fired right up with no security LED flashing. Whew, that had my pulse racing a bit.

A strip of electrical tape slipped over the top finishes the job. After a few days of operation I may pull the tape back and pour a little glue alongside the holder, just in case the tape loses it's grip and the holder jiggles out when bouncing over a pot hole.
The project will take about an hour and is really pretty easy. Be sure to pick up the Torx driver (T-15) before you start. Good luck!
-MK
Other keywords: chip disable fob Securecode