Engine warning light comes on, diagnostic says

Hello
When the service engine soon light (Also called the check engine light) is turned on this is to alert you to the fact that powertrain control module (computer) has detected a failure somewhere in the systems it controls, this can be the transmission or the engine or emission system, there are fault codes set in the modules memory for these faults. What needs to happen now is to have the powertrain control module scanned with a special tool called an OBD2 electronic engine control scanner or a OBD2 code reader. Once the code(s) are read then you must perform the diagnostics for each code and make the appropriate repairs based on the findings of the diagnosis that was performed, this is called doing "Pinpoint" testing.

Not uncommon for Ford focus coil packs to play up I've replaced a few I would recommend, replace coil pack and have leads. If you have car serviced at the regular service interval the plugs should be ok.

What motor does the car have? 2.0 or 2.3 Sounds like a coil is breaking down and needs replaced

I would start with plug wires rubbing on something and created a short.and is not compleatly worn through. a cheep place to start. good luck with it.

with one hand on the throttle control and one "free" hand (PLEASE NOTE: there is a SERIOUS risk of getting shocked, be VERY careful)
with the car running, use a pair of insulated pliers, and one at a time pull a plug wire!
If the car tries to die, give it a little gas, and replace wire.
If there is "no change" then you have found the "dead" cylinder!
Hope this helps!!!
Good luck

Have the codes check, if it's a misfire have the injectors and wires going to them check

a flashing mil (malfunction indicate lamp) means the computer has detected a misfire. whether random or specific, you'll have to get the code read. autozone, aamoco do it for free

yes if 1 and 4 are on the same coil pack, thats the place to start and i think thats your answer

take it to your local autoparts store(prefferably Autozone) and tell them your check engine light is on. they will run a diagnostics free of charge. But note: the light must be lit(check engine light) when you go there or else they wont be able to run the diagnostics if the check engine light is off. this should narrow down your problem

Hi

Check your engine oil and coolant levels, and go from there !
Have a look in the hand book in the glove box ? to see if you can see what the light is warning you of !

Good Luck !

Let me know the outcome !

John.

A FixYa rating would be nice !!!