2002 Ford Focus

light will stay on till repair is done and misfire can be spark plug /wire/coil/injector/internal valvetrain /piston etc

Can you confirm cylinder two is getting spark ?
If it is, it could be something mechanical or the fuel injector.

Check wiring harness to fuel injectors where it runs through intake manifold - these chafe through and cause injectors to stay on or off. Also check engine grounds. 2 at back of head near firewall and one at drivers side engine mount (almost impossible to see)

Sounds like a vacuum leak
Also check out EGR Valve and TPS Sensor.

i would think a plugged fuel injector on # 6 cylinder could be the problem,or a big vacuum leak at that cylinder
a valve burnt/stuck could be but you dont see much of that anymore
could be coolant leaking into cylinder from leaky haed gasket but you would have to add coolant every so often
i would check #6 cyl. spark plug after driveing around a while if it looks new, ie no deposits on it then an injector would be what i would change next

missfire check spark plug wires and spark plugs

it could be u needd new spark plugs and the sparks or the timings offf change sparkplugs and plugs and ur gasfilter tat sud do it .

I have a 1999 ford escort 2.0, its got a miss on cylinder 3 and 4. I changed the wires and the coil pack but its still missing. When scanned I get code p1506, p0303 and p0304

It sounds like an ignition problem. Make sure your battery is good and connections are clean. I would start by replacing the plug wires and spark plugs. This is a good tune up procedure anyway and will increase your mileage some. Clean or change the air filter. The obvious thing is to make sure the oil is new and filled to the correct level, not overfilled. Your engine will love you. I hope this helps.

have you tried having your fuel injectors cleaned on it. the engine might not be getting enough gas at take off. it might also be that your gas tank fuel pump or the other fuel pump going bad