Getting a rapid misfire in cylinder 5 changed spark plugs ,cleared the code came back on the day later ???

Hello,
Your question lists codes p305p, and p305, which are not valid codes. Did you mean P0305? This is a diagnostic code referring to a misfire on cylinder #5. It looks like you've replaced parts that could be causing a misfire, but did not fix the problem.

A simple check to verify your misfire is not being caused by an ignition coil (the 4.8 liter engine has a coil-near-plug system, with one coil for each spark plug) is to swap the suspect coil (cylinder #5) with a coil from a different cylinder on your engine.

Cylinder #5 is the third one back from the front of the engine on the driver side of the engine. After you swap coils between a good cylinder and #5 cylinder, clear the codes and see if the misfire followed the coil- if a misfire code sets on the cylinder you moved the cylinder #5 coil to, you know the coil has a problem. That will at least help you rule out the remainder of the ignition system.

When was the last time you changed spark plugs/wires? That's the first thing you should check

If you changed the #5 Coil then the code was wrong

You get lots of wrong codes on a ford, as a bad coil
spikes the pcm when grounding out to fire the coils
secondary side

Try putting the old coil back & walking the new one to
another cylinder,may take many days & many miles of
driving to get it fix,but better than a shop guessing, because
they hate fords

Hi:
It seems that your intermittent problem could be a cheap fix,and you can try a few things that might fix or eliminate the problem. Since the code pointed to the #1 cylinder misfire, You could change out your spark plugs and spark plug wires as a possible cause. If it doesn't fix it, they were 5-6 years old, and a new set isn't a bad investment. If the problem persists, then you are looking at a ignition coil, coil pack, distributor cap/ rotor,depending on your particular engine. Often if you have an ignition module failing, it will affect all cylinders misfiring, often randomly , so once you change your plugs and wires, have someone clear the check engine light, so if it comes back on ,you can check to see what the new code problem is...I hope you get a cheap fix!

well the first thing you should do is check the compression in cyl number four the compression should be within 5-8 of the nearest cyl if you see a significant diffrence in pressure you have a week cylinder...also is there any discoloration on the number 4 spark plug a coolant soaked or fuel soaked spark plug can lead u in the right direction..lastly i would take a look at the exact fuel pressure you will need a gauge and take a look low or high fuel pressure can cause a misfire....keep in mind that a clogged catylitic convertor can also cause a misfire do to accesive back pressure give your convertor a tap and see if its rattling ....hopefully this can lead u in the right direction ...good luck

the p0302 code gives u a place to start u can have perfect maintainance with ur car but parts wear out ,go bad,or get damaged-- misfire in cylinder 2 can b a spark plug,a bad wire ,injector starting to clog -start with checking the plug and wire

Code P0301
Ignition Coil Pack
Ignition Cable
Spark plug
Clog or dirty fuel injector
Evap canister purge valve
Engine Compression
fuel pressure

you have 3 type of engine for your truck
2.3L 4 cylinder
3.0L 6 Cylinder
4.0L 6 Cylinder

need to know that type Engine

The reason why the service light come on because it is a hard code
not a soft code.

Let me know

When cleaning your engine, water/degreaser went down the spark plug ports. Try using a air compressor blow gun to remove the moisture from around the spark plugs and boots. The water was causing the engine to misfire on 3 cylinders at first and as the ports started to evaporate the moisture, the less misfiring was occuring. Dry thouroughly and hopefully coils do not have damage to them. Also check to make sure the boot is making good contact with the spark plug.

I have a corolla and had #4 cylinder misfire also diagnosed at autozone. After changing the spark plugs, problem persisted, along with the same error code, so they recommended changing the spark plug wires, and that is what fixed it. I would have changed the rotor cap too, but was low on dough. Glad that was not the problem.

This is a pretty common problem. I would change your valve cover gaskets. They run around ~ 50 bucks. If they are bad it will leak oil into spark plug well and cause a misfire. Very known on the 740.. Also if tune was not anytime not too long ago id change spark plugs while you at it. Then clear the computer and if you still get misfire on 8 try changing the ignition coil which is right about the cylinder with cylinder ignition coil 5. clear the computer. if you get random misfire and misfire cyclinder 5 after then its your ignition coil. parts store runs around 100 bucks