At least 98% of the time, “It’s the computer” is the default diagnosis from mechanics who have no clue as to the actual source of a problem.
For the sake of your wallet, please do not allow the current mechanic to talk you into replacing the ECM. Try to find a mechanic who has better diagnostic skills.
yeah i have taken it to 3 mechanics and im just repeating what they have been telling me which is why i sound like an idiot. 
I agree with VDCdriver’s statements about the computer being blamed for all of the world’s ills and also agree that you should not let any of them talk you into replacing that computer.
For what it’s worth, as a mechanic (a.k.a. parts replacer…) of near 50 years I can count on one hand the number of faulty computers I’ve run across and most of those failed because of someone; not because of failure due to design or age. In other words; electronic murder.
The automotive ECM/PCM/ECU to me is an amazingly reliable piece of tech considering the vibrations, temperature extremes, and voltage fluctuations it has to go through.
Do NOT think of yourself as an idiot. You are not. You are ignorant of the system which only means that you do not know. That does not make you stupid at all. Every person on Earth, me included, is ignorant because no human knows all there is to know about every subject.
Well i really appreciate everyone pointing me to a compression test. I was about to replace all the fuel injectors and was looking into replacing the computer. But if its a blown head gasket or a worn piston i guess i’ll be at a loss any way since I could probably not afford to have that repaired anyway.
I hope those three mechanics weren’t named Moe, Larry, and Curley.
Nope, they were, Manny, Mo, and Jack. 
Ask your shop to verify the alternator output voltage is ok, around 13-14 volts when engine is warmed up, battery charged. Overly high alternator voltage could cause the spark voltage & current to be too much. My guess, that’s not the problem. The brown ring at the lower limit of the porcelain doesn’t necessary mean the spark plug is “burned out”, could just be a little oil from a valve cover leak. If plug is burned out, that would show up at the tip of the plug, which for some reason you haven’t yet shown.
Misfires are a pretty common complaint here. Seldom caused by spark plug damage. Suggest to go back to square one. Common causes of misfire are (1) incorrect fuel/air mixture; (2) incorrect compression; (3) spark problem, (4) exhaust system problem.
Diagnosis is done by fuel trim testing, compression testing, ignition system testing, and exhaust system inspection/testing. Suggest to ask your shop to start a fuel trim test, report the results here for more ideas.
Is your engine a coil-on-plug design?
Manny is on vacation, moe will be here later and Jacks off
Yes its coil on plug.
Looking at the old spark plugs, they do have oil on them, could oil from a valve gasket leak getting onto the spark plugs cause them to misfire?
Also if it is a compression issue would it be on and off, or more consistently bad? Some days i start it and it runs perfectly fine, other days i start it and its running rough, which i think is why im having a problem getting the mechanics to look at it. They’ll turn it on and be like “seems like its running fine”.
A 12-13 year old vehicle?
I wonder if the timing chain is stretched?
Tester
Probably Manny, Moe, and Jack. The Pep Boys.
What’s the difference? 
I pulled the current spark plugs out (they havent been in that long, but are already misfing) and from what i can tell it looks like they have carbon fouling on them. From running some searches on the internet that would mean the engine is running too rich, correct? What would be the best course of action to determine the cause?
My old solutions to a problem like this don’t seem to apply anymore to these newer cars so I am going to suggest that maybe you should try a different brand or grade of fuel.
The top three look ok to me, not much signs of carbon fouling I can see there. The bottom one looks different, not fouled, but has more carbon on it. That could be normal for your engine though, some plug locations get more oil/egr residue than others. Does your misfire code correspond to that particular cylinder?
Unexplained misfires, beyond simple visual inspection, common diagnostic method is to swap parts from cylinder to cylinder. If misfire follows part swap, good chance the cause of the problem is identified. Spark plugs, coils, wires, fuel injectors are common swap items, depends on the engine’s configuration which is easiest to do.
Evidence of overly rich operation (other than bottom plug) at this point is scanty, but a fuel trim test is where a shop would start. Fuel trim is done w/scan tool. Not all scan tools are able to do fuel trim tests. Given the appearance of bottom spark plug, if I had this problem I’d do a compression test first.
One other note: If those plugs had been in there for 15,000 + miles I’d be a little concerned about coolant getting into the cylinders. B/c of the pristine-white appearance of the porcelain on the top three plugs. Coolant will steam clean the spark plugs. If these plugs are recently installed, less of a concern.
Hi lots of sensible suggestions. "Thinking around the point’ is part of the ‘diagnosis neurosis’ one can suffer when problems don’t leap out as having obvious solutions and worse…are intermittent… as your helpers realise.
When dealing with yours in a away it isn’t intermittent. It happens after running ok…then something else happens…replaced parts, time delay, perhaps weather…
When working with plugs and individual coils, always mark which cylinder they are from. If you don’t you have no points for comparisons and accurate recall.
Does exhaust smoke differently when ‘missing’…does pressure of exhaust gases against feel less whe missing occurs (exhaust faults).
Keep a diary each day on Kms, weather, last fuel fill and where , last time removing parts, symptoms and how when and where. Do you have electric fuel pump or mechanical?..or both?
As well as fuel mixture variations through pump intermittency and/or loss of pressure , water in fuel, filters dirty, obstacle in line, intermittent or faulty injectors… missing can occur through faulty catalyctics and mufflers. Is it all through one cylinder…it helps to do a systematic and well recorded isolation test run.
Looking at your plugs…which I gather have been several times replaced…all look ok but one different as noted by others. To me that’s not oiled-up…it’s just not firing cleanly. What cylinder is it? Is it the same every time or do you just put them back ‘willy nilly’…not so sure about the gaps…what are you using to check? are you measuring at least wide gap?
Spark plugs should always be tensioned ‘in’ . Overtigtening can cause gap changes…however my immediate impression of your plugs is that the sealing washers have not been crushed. I could be wrong but…are you seating plugs to correct tension? If not seating properly so as to seal engine at all temperatures you can get malfunction
The plug with the slightly darker centre electrode,it seems the least worn so maybe not firing as often as the others.
One has to be careful with electronic ignitions that shorting a coil toblock does not cause a failure at the ECU. Better to pull a coil to stop firing at any cylinder if there is a warning on shorting…after all…plugs do sometimes ‘short’ across gap.So pull ALL plugs, marking their cylinger number onto them…not just laying down in order…they can roll away or one forgets…
Do compression test 3 times and record figures
Replace plugs in ‘correct’ cylinders run car normally until fault arises…I’d try every half hour for two hours in morning and same in evening (different atmospherics) which might be when you start if some other day. So…if you replace plugs at I don’t know…say 3pm…start a few times (spaced) from 6pm to 8 pm then again the next morning as an initial check, This may tell you something is happening overnight in the engine…like coolant getting in…or some fuel flooding occurring…or some oil seeping-in down say a valve guide (usually giving oil smoke at startup)
Pull and replace coils one at a time from 1 to 4 to see whether the misfiring cylinder shows up…replace the plug from the missing cylinder. with a new one…(kept for testing purposes)
Does the fault go away (for a short time or longer…all recorded in diary. If not try a second test plug.
When fault re-arises go through same procedure …record.
If possible to do without damage…swap alternate coil ends (keep in correct firing order) with another…record which cylinder it is from. Does the same cylinder give a miss?..or does the cylinder from which you purloined it give a miss now? record.
What this does is give an orderly testing regime…all recorded.
A miss can also occur from hydraulic lifter faults …but that would likely always be same cylinder if motor starts and runs.A miss can occur from coolant getting into a cylinder (setting aside valve problems and ring problems.) A compression test should give you an inkling and a cooling system pressure test may back it up.
I’d first of all every time , after doing the testing regime as above…first see if replacing that blacker-electrode plug with a new plug. …keep always in same cylinder for this test…makes any difference. I am working here towards analysing possibilities without computer checks…My regards
Looking the spark plugs, I notice unusual deposits on the top spark plug, none on the next one down, again on the third plug. and really a lot on the forth.
Are you using any kind of fuel additives?
Tester
Not sure if this is your problem but I had a vehicle which had the same issues turned out to be a starting of a blown head gasket did not figure out until it finally blew same cylinder of the misfire?
