Rough Idel & Engine Miss

Mary, PLEASE be sure this looks like your motor even thoe its a 2.3 it still should be the same valve cover .if its not let me know an i'll look further . if this helped you please let me know.
Woody

With out actually hearing it or knowing what engine is in it it hard to be 100% sure but, it depends on if its the 2.0 spi or the 2.0 ztec dual overhead cam, if its the spi, that particular engine is known for dropping the valve seats out of the head, the seats are the sealing steel sealing ring that the valve closes against during different strokes of the engine. its an aluminum head and a steel seat, they will expand and contract at different rates, if the seat doesnt have enough interference when pressed in it can fall out and damage the head, valve and piston, when the seat comes loose you will have a misfire and a noise coming from the engine, now.... that being said it could be a timing belt that has partially slipped... this is a real tough call without seeing and or hearing the car, what codes does it have?, whats the fuel pressure etc.... This is one you should have a qualified tech look at... sorry.

what is your question

Ignition misfire, leaking intake gaskets, faulty fuel injector. Is the check engine light on and blinking with engine running?

As long as everything you've mentioned is in good working condition I would test your O2 sensors and your mass air flow sensor both could cause a rough erratic idle and even a miss if the O2 sensors send a bad signal to ecu which would affect fuel trim ratio

Try this website hope it helps.http://myfordfocus.com/underthehood.htm

there is a recall for the fuel pump, but only applies to certain focuses according to the build date. if your car doesn't fall within the build date, it is a customer pay item... the car may very well need a fuel pump, i would say that is probably the best possibility. the other thing about recalls is they do expire, or if the car has already had the recall done you are not able to have the recall performed again. if it has the ztec engine i have seen valve cover gaskets blow out and soak the spark plugs with oil, this also causes the problem your having.hope this helps you and good luck---also what parts does the dealer think it is?

have you given the car a tune up yet? is the check engine light on? if so, have you had that checked? that car also had a couple of recalls, have you taken it in to have the recalls repaired? I "HAD" a 2000 ford focus se 2.0L. the volume control in the factory radio has the speed control as in the faster you went the higher the volume went, so the miss in the engine might be being sent through the system and it thinks that you want to over come the roadnoise. as far as I can remember it is adjustable.

With having that many miles and the light being on with a code of O2 sensor, I'd say start there. Make sure which O2 sensor it is first, pre or post convertor. It's getting close to another tune up, but check your plugs first.

IS YOUR LOUD VIBRATION A LOUD RATTLE IF SO IT COULD BE YOUR CAT BREAKING UP THIS WILL CAUSE BAD RUNNING ..GIVE YOUR ENGINE A GOOD REV 3 or 4 TIMES OUT OF GEAR AND LISTEN FOR A RATTLE,,,,, HOPE THIS HELPS IF NOT CHECK THAT THE EXHAUST IS NOT BLOCKED ?? BEST OF LUCK-ELL BOY.