really, i consider the scan tools are free.
if you use it 1 time
, ( & you will, if you own the car long enough)
it pays back big time. ( a true investment) < think about it?
anecdotal , yes, (my motor ran,bad, the skipped tune up was the cause,) ho hummm
reading 1000 posts on misfire , many anecdotal for sure.
what is better is diagnosis.... using tools, gauges and meters.
for and idea of how futile guessing is , see here.
at first blush it is 1 of 4 ways (yes, it is in physics)
but is it really ? no , it's a vast number of ways.
but , if you read my text file sig link
post the symptoms and if you want to guess or test?
no body ever states that. here...
if you take it to a real mechanic , you don't want him to guess, do you?
you do know there are great books on topic , right?, (open hood and....)
not to mention ASE classes.
the first steps, are the most crucial
most open the hood and don't recognize a thing.
pretty hard to run with that.... no pun.
in school you learn to work on 50 year generations of engines, and the parts under the hood all start to look the same.
some parts only look different, but are the same.
for the best help, post your symptoms, (engine for example) cold,hot, idling, cruising , hills , flat ground, and WOT.
with input like that , which i call the Good the bad and the ugly , really does help the blind guys. (and missing parts and mods)