General Hacks

Instrument Cluster Test Mode
The Instrument cluster of all US-Spec Foci have a built in test-mode complete with digital speedometer, tachometer and diagnostic readings... Wanna access it? :)
Installing a Performance Chip
Installing a performance chip can work miracles by re-calibrating the way your car's computer handles engine management.
Airbox Resonator Removal
It's debatable whether this Hack does much for performance, but it adds a nice sound to the engine under load.
Large Debris Deflector Removal.
Make your intake take in a little more.
Installing Aftermarket Spark Plug Wires
Installing Spark Plug Wires with a larger core can give you a smoother running engine, better throttle response, and a more complete fuel burn. Plus, they just look good!
Finding your PCM Code
To order a performance chip, you need to tell the retailer what PCM Code you have. This indicates the version of Ford's engine management software you are running on the computer inside your car. This is very important, because performance chips are much like a software upgrade for your car's Powertrain Control Module. If the software upgrade is not compatable with the software you're currently running, your on-board computer will not work properly.
Replacing Fuel Injectors
Whether you're looking for more fuel flow, or just replacing a bad fuel injector, this will walk you though the process.
SVT Snorkel Install
The new airbox snorkel found on the Focus SVT has a much larger, smoother cross-section than the base stock Zetec snorkel. The following instructions will allow you to cleanly install this snorkel on your Focus, and your engine will breathe better as the result.