Originally Posted by whynotthinkwhynot
You car does not have a cabin air filter. You can find an earlier 00-04 Focus in the junkyard and rob the cabin air filter holder. It will fit in a 05-07 in place of the screen that is in there now.
You do not have an air filter to change. 05-07 were equipped with a lifetime air filter. Your owner's manual will tell you how to test it. Most of us replace that with an aftermarket oil/cotton filter and CAI instead of purchasing a new $200 lifetime filter when the OEM doesn't flow correctly.
Cleaning the MAF is not a bad idea, and costs about $7 for a can of spray MAF cleaner. Around 100k miles is when I replaced my coil boots. You might have noticed that you don't have plug wires and a distributor or even a coil pack like older vehicles. You have coil on plug ignition. Those are the coils that sit on top of the valve cover. We have had problems with the clips connecting the coil power wires- so check those to be sure these are all connected and clipped in place. To replace the boots, remove the coil and boot from the plug. Twist the boot to break it loose, then fold the open end of the boot back towards the top of the coil, and it will pop loose. You can also just pull or push it off the coil. A new boot will cost $5-8 each, and will come with a new spring and solid conductor.
Fuel filters should be changed every 25-30k miles. There is really not much you have to do to this car as far as a "tune-up". Plugs every 75k or so if you use platinum or iridium. NO, they do not last 100k. Coil boots are changed right around the same time, you might get 2 plug changes. The MAF should be cleaned every 25-30k when you change the fuel filter. You can check the PCV at this time- but it's very difficult. As far as fluids go, just keep an eye on them, and change as needed. If you have an AT, then you might consider changing fluid and filter around 100k, or 60k or so. From what I understand, the new fluids last much longer than the old fluids did.
This may be a silly question. Aside of the car running poorly. Does a check engine light come on indicating, time for a change? The OEM filter not flowing correctly, leaves me to wonder if it would cause other problems within the engine.
Any idea what the life expectancy is for the OEM filter? My 07 has one of those maintenance free filters. IMHO that and the PCV being behind the manifold, is not one of Fords better ideas. Thanks